diff --git a/plots/crossword-basic/implementations/highcharts.py b/plots/crossword-basic/implementations/highcharts.py
new file mode 100644
index 0000000000..78e7d124bc
--- /dev/null
+++ b/plots/crossword-basic/implementations/highcharts.py
@@ -0,0 +1,234 @@
+""" pyplots.ai
+crossword-basic: Crossword Puzzle Grid
+Library: highcharts unknown | Python 3.13.11
+Quality: 91/100 | Created: 2026-01-15
+"""
+
+import tempfile
+import time
+import urllib.request
+from pathlib import Path
+
+import numpy as np
+from highcharts_core.chart import Chart
+from highcharts_core.options import HighchartsOptions
+from highcharts_core.options.series.heatmap import HeatmapSeries
+from selenium import webdriver
+from selenium.webdriver.chrome.options import Options
+
+
+# Data - Create a 15x15 crossword grid with 180-degree rotational symmetry
+np.random.seed(42)
+grid_size = 15
+
+# Generate symmetric black cell pattern (1 = black/blocked, 0 = white/entry)
+grid = np.zeros((grid_size, grid_size), dtype=int)
+
+# Define black cells for one half (will be mirrored for symmetry)
+black_cells = [
+    (0, 4),
+    (0, 10),
+    (1, 4),
+    (1, 10),
+    (2, 7),
+    (3, 0),
+    (3, 5),
+    (3, 9),
+    (4, 3),
+    (4, 8),
+    (4, 13),
+    (5, 6),
+    (5, 11),
+    (6, 1),
+    (6, 2),
+    (6, 10),
+    (6, 14),
+    (7, 7),
+]
+
+# Place black cells with 180-degree symmetry
+for r, c in black_cells:
+    grid[r, c] = 1
+    grid[grid_size - 1 - r, grid_size - 1 - c] = 1
+
+# Calculate clue numbers - number cells that start words (across or down)
+numbers = {}
+clue_num = 1
+for r in range(grid_size):
+    for c in range(grid_size):
+        if grid[r, c] == 1:
+            continue
+        starts_across = (c == 0 or grid[r, c - 1] == 1) and (c < grid_size - 1 and grid[r, c + 1] == 0)
+        starts_down = (r == 0 or grid[r - 1, c] == 1) and (r < grid_size - 1 and grid[r + 1, c] == 0)
+        if starts_across or starts_down:
+            numbers[(r, c)] = clue_num
+            clue_num += 1
+
+# Prepare heatmap data - black cells = 1, white cells = 0
+heatmap_data = []
+for r in range(grid_size):
+    for c in range(grid_size):
+        heatmap_data.append([c, grid_size - 1 - r, int(grid[r, c])])
+
+# Create chart
+chart = Chart(container="container")
+chart.options = HighchartsOptions()
+
+# Chart configuration
+chart.options.chart = {
+    "type": "heatmap",
+    "width": 3600,
+    "height": 3600,
+    "backgroundColor": "#ffffff",
+    "marginTop": 120,
+    "marginBottom": 100,
+    "marginLeft": 100,
+    "marginRight": 100,
+}
+
+# Title
+chart.options.title = {
+    "text": "crossword-basic · highcharts · pyplots.ai",
+    "style": {"fontSize": "48px", "fontWeight": "bold"},
+}
+
+# Remove colorAxis legend
+chart.options.color_axis = {"min": 0, "max": 1, "stops": [[0, "#ffffff"], [1, "#000000"]], "visible": False}
+
+# X-axis (columns 1-15)
+chart.options.x_axis = {
+    "categories": [str(i + 1) for i in range(grid_size)],
+    "title": {"text": None},
+    "labels": {"style": {"fontSize": "28px"}},
+    "lineWidth": 2,
+    "lineColor": "#000000",
+    "tickWidth": 0,
+    "tickLength": 0,
+    "startOnTick": False,
+    "endOnTick": False,
+}
+
+# Y-axis (rows A-O)
+row_labels = [chr(65 + i) for i in range(grid_size)]
+chart.options.y_axis = {
+    "categories": list(reversed(row_labels)),
+    "title": {"text": None},
+    "labels": {"style": {"fontSize": "28px"}},
+    "lineWidth": 2,
+    "lineColor": "#000000",
+    "tickWidth": 0,
+    "tickLength": 0,
+    "startOnTick": False,
+    "endOnTick": False,
+    "reversed": False,
+}
+
+# Legend disabled
+chart.options.legend = {"enabled": False}
+
+# Create heatmap series
+series = HeatmapSeries()
+series.name = "Grid"
+series.data = heatmap_data
+series.border_width = 2
+series.border_color = "#000000"
+series.data_labels = {"enabled": False}
+
+chart.add_series(series)
+
+# Add clue numbers as annotations
+annotations = []
+for (r, c), num in numbers.items():
+    annotations.append(
+        {
+            "point": {"x": c, "y": grid_size - 1 - r, "xAxis": 0, "yAxis": 0},
+            "text": str(num),
+            "align": "left",
+            "verticalAlign": "top",
+            "x": -85,
+            "y": -75,
+            "style": {"fontSize": "28px", "fontWeight": "bold", "color": "#000000"},
+            "backgroundColor": "transparent",
+            "borderWidth": 0,
+            "shadow": False,
+        }
+    )
+
+chart.options.annotations = [{"labels": annotations, "draggable": ""}]
+
+# Plot options for heatmap - ensure all cells have visible borders
+chart.options.plot_options = {
+    "heatmap": {
+        "borderWidth": 3,
+        "borderColor": "#333333",
+        "dataLabels": {"enabled": False},
+        "colsize": 1,
+        "rowsize": 1,
+    }
+}
+
+# Download Highcharts JS and heatmap module
+highcharts_url = "https://code.highcharts.com/highcharts.js"
+with urllib.request.urlopen(highcharts_url, timeout=30) as response:
+    highcharts_js = response.read().decode("utf-8")
+
+heatmap_url = "https://code.highcharts.com/modules/heatmap.js"
+with urllib.request.urlopen(heatmap_url, timeout=30) as response:
+    heatmap_js = response.read().decode("utf-8")
+
+annotations_url = "https://code.highcharts.com/modules/annotations.js"
+with urllib.request.urlopen(annotations_url, timeout=30) as response:
+    annotations_js = response.read().decode("utf-8")
+
+# Generate HTML with inline scripts
+html_str = chart.to_js_literal()
+html_content = f"""<!DOCTYPE html>
+<html>
+<head>
+    <meta charset="utf-8">
+    <script>{highcharts_js}</script>
+    <script>{heatmap_js}</script>
+    <script>{annotations_js}</script>
+</head>
+<body style="margin:0;">
+    <div id="container" style="width: 3600px; height: 3600px;"></div>
+    <script>{html_str}</script>
+</body>
+</html>"""
+
+# Write temp HTML and take screenshot
+with tempfile.NamedTemporaryFile(mode="w", suffix=".html", delete=False, encoding="utf-8") as f:
+    f.write(html_content)
+    temp_path = f.name
+
+chrome_options = Options()
+chrome_options.add_argument("--headless")
+chrome_options.add_argument("--no-sandbox")
+chrome_options.add_argument("--disable-dev-shm-usage")
+chrome_options.add_argument("--disable-gpu")
+chrome_options.add_argument("--window-size=3600,3600")
+
+driver = webdriver.Chrome(options=chrome_options)
+driver.get(f"file://{temp_path}")
+time.sleep(5)
+driver.save_screenshot("plot.png")
+driver.quit()
+
+Path(temp_path).unlink()
+
+# Also save HTML for interactive version
+html_output = f"""<!DOCTYPE html>
+<html>
+<head>
+    <meta charset="utf-8">
+    <script src="https://code.highcharts.com/highcharts.js"></script>
+    <script src="https://code.highcharts.com/modules/heatmap.js"></script>
+    <script src="https://code.highcharts.com/modules/annotations.js"></script>
+</head>
+<body style="margin:0;">
+    <div id="container" style="width: 100%; height: 100vh;"></div>
+    <script>{html_str}</script>
+</body>
+</html>"""
+with open("plot.html", "w", encoding="utf-8") as f:
+    f.write(html_output)
diff --git a/plots/crossword-basic/metadata/highcharts.yaml b/plots/crossword-basic/metadata/highcharts.yaml
new file mode 100644
index 0000000000..6a48335f13
--- /dev/null
+++ b/plots/crossword-basic/metadata/highcharts.yaml
@@ -0,0 +1,203 @@
+library: highcharts
+specification_id: crossword-basic
+created: '2026-01-15T22:43:04Z'
+updated: '2026-01-15T22:45:44Z'
+generated_by: claude-opus-4-5-20251101
+workflow_run: 21048827576
+issue: 3805
+python_version: 3.13.11
+library_version: unknown
+preview_url: https://storage.googleapis.com/pyplots-images/plots/crossword-basic/highcharts/plot.png
+preview_thumb: https://storage.googleapis.com/pyplots-images/plots/crossword-basic/highcharts/plot_thumb.png
+preview_html: https://storage.googleapis.com/pyplots-images/plots/crossword-basic/highcharts/plot.html
+quality_score: 91
+review:
+  strengths:
+  - Excellent implementation of crossword grid using Highcharts heatmap
+  - Perfect 180-degree rotational symmetry in black cell placement
+  - Clue numbering algorithm correctly identifies word start positions
+  - Clean monochrome design suitable for printing
+  - Square 1:1 aspect ratio as specified
+  - Both PNG and HTML outputs generated
+  weaknesses:
+  - Clue numbers could be slightly larger for better visibility at smaller display
+    sizes
+  - Axis labels are functional but lack descriptive text
+  image_description: The plot displays a 15x15 crossword puzzle grid with white entry
+    cells and black blocking cells. The title "crossword-basic · highcharts · pyplots.ai"
+    appears at the top in bold black text. Row labels (A-O) are displayed on the left
+    Y-axis, and column numbers (1-15) appear along the bottom X-axis. Black cells
+    form a symmetric pattern typical of newspaper crosswords, with 180-degree rotational
+    symmetry visible. Clue numbers (1-73) are positioned in the top-left corners of
+    cells that start across or down words. The grid has clean black borders separating
+    all cells, and the overall monochrome design follows traditional crossword conventions.
+  criteria_checklist:
+    visual_quality:
+      score: 36
+      max: 40
+      items:
+      - id: VQ-01
+        name: Text Legibility
+        score: 9
+        max: 10
+        passed: true
+        comment: Title, axis labels, and clue numbers are readable, though clue numbers
+          could be slightly larger
+      - id: VQ-02
+        name: No Overlap
+        score: 8
+        max: 8
+        passed: true
+        comment: No overlapping text elements
+      - id: VQ-03
+        name: Element Visibility
+        score: 8
+        max: 8
+        passed: true
+        comment: Grid cells clearly visible with appropriate sizing
+      - id: VQ-04
+        name: Color Accessibility
+        score: 5
+        max: 5
+        passed: true
+        comment: Pure black and white, perfectly accessible
+      - id: VQ-05
+        name: Layout Balance
+        score: 4
+        max: 5
+        passed: true
+        comment: Good use of canvas, slight imbalance in margins
+      - id: VQ-06
+        name: Axis Labels
+        score: 1
+        max: 2
+        passed: true
+        comment: Row (A-O) and column (1-15) labels present but no descriptive labels
+      - id: VQ-07
+        name: Grid & Legend
+        score: 1
+        max: 2
+        passed: true
+        comment: Clean grid lines, no legend needed
+    spec_compliance:
+      score: 25
+      max: 25
+      items:
+      - id: SC-01
+        name: Plot Type
+        score: 8
+        max: 8
+        passed: true
+        comment: Correct crossword grid visualization using heatmap
+      - id: SC-02
+        name: Data Mapping
+        score: 5
+        max: 5
+        passed: true
+        comment: Grid cells correctly mapped with black/white values
+      - id: SC-03
+        name: Required Features
+        score: 5
+        max: 5
+        passed: true
+        comment: White entry cells, black blocking cells, numbered positions all present
+      - id: SC-04
+        name: Data Range
+        score: 3
+        max: 3
+        passed: true
+        comment: Full 15x15 grid displayed
+      - id: SC-05
+        name: Legend Accuracy
+        score: 2
+        max: 2
+        passed: true
+        comment: No legend needed for this plot type
+      - id: SC-06
+        name: Title Format
+        score: 2
+        max: 2
+        passed: true
+        comment: 'Correct format: crossword-basic · highcharts · pyplots.ai'
+    data_quality:
+      score: 18
+      max: 20
+      items:
+      - id: DQ-01
+        name: Feature Coverage
+        score: 7
+        max: 8
+        passed: true
+        comment: Shows symmetric black cell pattern and numbered clues, demonstrates
+          crossword structure well
+      - id: DQ-02
+        name: Realistic Context
+        score: 7
+        max: 7
+        passed: true
+        comment: Authentic newspaper-style crossword layout
+      - id: DQ-03
+        name: Appropriate Scale
+        score: 4
+        max: 5
+        passed: true
+        comment: 15x15 is standard size, 73 clues is realistic
+    code_quality:
+      score: 9
+      max: 10
+      items:
+      - id: CQ-01
+        name: KISS Structure
+        score: 3
+        max: 3
+        passed: true
+        comment: 'Linear flow: imports → data → plot → save'
+      - id: CQ-02
+        name: Reproducibility
+        score: 3
+        max: 3
+        passed: true
+        comment: Uses np.random.seed(42)
+      - id: CQ-03
+        name: Clean Imports
+        score: 2
+        max: 2
+        passed: true
+        comment: All imports are used
+      - id: CQ-04
+        name: No Deprecated API
+        score: 0
+        max: 1
+        passed: false
+        comment: Using older annotation syntax
+      - id: CQ-05
+        name: Output Correct
+        score: 1
+        max: 1
+        passed: true
+        comment: Saves as plot.png and plot.html
+    library_features:
+      score: 3
+      max: 5
+      items:
+      - id: LF-01
+        name: Distinctive Features
+        score: 3
+        max: 5
+        passed: true
+        comment: Uses Highcharts heatmap with annotations module, but could leverage
+          more interactive features
+  verdict: APPROVED
+impl_tags:
+  dependencies:
+  - selenium
+  techniques:
+  - annotations
+  - html-export
+  patterns:
+  - data-generation
+  - matrix-construction
+  - iteration-over-groups
+  dataprep: []
+  styling:
+  - custom-colormap