diff --git a/client/components/modal/alert.jsx b/client/components/modal/alert.jsx
new file mode 100644
index 0000000..41f876f
--- /dev/null
+++ b/client/components/modal/alert.jsx
@@ -0,0 +1,33 @@
+import { Component, createRef } from 'react'
+import { ModalHeader, ModalBody, Button } from 'reactstrap'
+
+export default class Alert extends Component {
+  constructor(props) {
+    super(props)
+    this.dismissButtonRef = createRef()
+  }
+  handleDismissClick = () => {
+    this.props.close()
+  }
+  componentDidMount() {
+    setTimeout(() => this.dismissButtonRef.current.focus())
+  }
+  render() {
+    const { message } = this.props
+    const { handleDismissClick, dismissButtonRef } = this
+    return (
+      <>
+        <ModalHeader className="py-4 justify-content-center">
+          { message }
+        </ModalHeader>
+        <ModalBody className="d-flex justify-content-center">
+          <Button
+            color="secondary"
+            innerRef={dismissButtonRef}
+            name="dismiss-modal"
+            onClick={handleDismissClick}>Dismiss</Button>
+        </ModalBody>
+      </>
+    )
+  }
+}
diff --git a/client/components/modal/index.js b/client/components/modal/index.js
new file mode 100644
index 0000000..3f1b8ba
--- /dev/null
+++ b/client/components/modal/index.js
@@ -0,0 +1 @@
+export { default as Alert } from './alert'
diff --git a/client/containers/authenticate.jsx b/client/containers/authenticate.jsx
index 3ad7cac..7e0c237 100644
--- a/client/containers/authenticate.jsx
+++ b/client/containers/authenticate.jsx
@@ -1,11 +1,13 @@
 import { FORM_ERROR } from 'final-form'
 import { Component } from 'react'
 import { LoginForm } from '../components/login'
+import { Alert } from '../components/modal'
+import { Modal } from '../containers'
 import { withServices } from '../services/context'
 
 class Authenticate extends Component {
   handleLogin = async credentials => {
-    const { api, router, session } = this.props.services
+    const { api, modal, router, session } = this.props
     const { status, data } = await api.post('/auth/login', credentials, {
       validateStatus: status => [201, 400, 401].includes(status)
     })
@@ -14,19 +16,34 @@ class Authenticate extends Component {
         session.start(data)
         router.push('/')
         return
-      default:
+      case 400:
+        throw new Error('NOT IMPLEMENTED')
+      case 401:
+        modal.open({
+          render({ close }) {
+            return (
+              <Alert
+                close={close}
+                message="Incorrect username or password." />
+            )
+          }
+        })
         return { [FORM_ERROR]: 'Invalid login.' }
     }
   }
   render() {
     return (
-      <LoginForm onSubmit={this.handleLogin}/>
+      <>
+        <LoginForm onSubmit={this.handleLogin} />
+        <Modal />
+      </>
     )
   }
 }
 
-export default withServices(Authenticate, ({ api, router, session }) => ({
+export default withServices(Authenticate, ({ api, router, modal, session }) => ({
   api,
+  modal,
   router,
   session
 }))
diff --git a/client/containers/index.js b/client/containers/index.js
index 7342bda..26e37ef 100644
--- a/client/containers/index.js
+++ b/client/containers/index.js
@@ -1 +1,2 @@
 export { default as Authenticate } from './authenticate'
+export { default as Modal } from './modal'
diff --git a/client/containers/modal.jsx b/client/containers/modal.jsx
new file mode 100644
index 0000000..493b50c
--- /dev/null
+++ b/client/containers/modal.jsx
@@ -0,0 +1,48 @@
+import noop from 'lodash/noop'
+import { Component } from 'react'
+import { Modal as ReactstrapModal } from 'reactstrap'
+import { withServices } from '../services'
+
+class Modal extends Component {
+  constructor(props) {
+    super(props)
+    this.state = {
+      isOpen: false,
+      response: null
+    }
+    this.unsubscribe = noop
+  }
+  onClosed = () => {
+    this.props.modal.close(this.state.response)
+  }
+  close = response => {
+    this.setState({ isOpen: false, response })
+  }
+  componentDidMount() {
+    this.unsubscribe = this.props.modal.subscribe(({ isOpen }) => {
+      this.setState({ isOpen })
+    })
+  }
+  componentWillUnmount() {
+    this.unsubscribe()
+  }
+  render() {
+    const { isOpen } = this.state
+    const { modal: { render } } = this.props
+    const { close, onClosed, onOpened } = this
+    return (
+      <ReactstrapModal
+        autoFocus
+        centered
+        isOpen={isOpen}
+        onClosed={onClosed}
+        onOpened={onOpened}>
+        { render({ close }) }
+      </ReactstrapModal>
+    )
+  }
+}
+
+export default withServices(Modal, ({ modal }) => ({
+  modal
+}))
diff --git a/client/lib/index.js b/client/lib/index.js
index 80d2cde..d0020a6 100644
--- a/client/lib/index.js
+++ b/client/lib/index.js
@@ -1,2 +1,3 @@
 export { default as authorize } from './authorize'
 export { default as isServer } from './is-server'
+export { default as Model } from './model'
diff --git a/client/lib/model.js b/client/lib/model.js
new file mode 100644
index 0000000..6a7dbe1
--- /dev/null
+++ b/client/lib/model.js
@@ -0,0 +1,29 @@
+export default class Model {
+  constructor() {
+    this._listeners = []
+    this._model = this.init
+  }
+  get init() {
+    return {}
+  }
+  subscribe(listener) {
+    const listenerIndex = this._listeners.push(listener) - 1
+    listener(this._model)
+    return () => {
+      this._listeners.splice(listenerIndex, 1)
+    }
+  }
+  update(updater) {
+    switch (typeof updater) {
+      case 'function':
+        this._model = { ...this._model, ...updater(this._model) }
+        break
+      case 'object':
+        this._model = { ...this._model, ...updater }
+        break
+      default:
+        throw new Error('updater passed to StateModel.setState must be a Function or an Object.')
+    }
+    this._listeners.forEach(listener => listener(this._model))
+  }
+}
diff --git a/client/pages/_app.jsx b/client/pages/_app.jsx
index 84b0f69..942a316 100644
--- a/client/pages/_app.jsx
+++ b/client/pages/_app.jsx
@@ -3,7 +3,7 @@ import Router from 'next/router'
 import NProgress from 'nprogress'
 import App, { Container } from 'next/app'
 import { isServer } from '../lib'
-import { Provider, initApi, initSession } from '../services'
+import { Provider, initApi, initModal, initSession } from '../services'
 
 export default class extends App {
   static async getInitialProps({ Component, router, ctx }) {
@@ -22,6 +22,7 @@ export default class extends App {
   constructor(props, ...args) {
     super(props, ...args)
     this.api = initApi()
+    this.modal = initModal()
     this.session = initSession(props.user)
   }
   componentDidMount() {
@@ -32,12 +33,12 @@ export default class extends App {
   }
   render() {
     const { router } = Router
-    const { api, session } = this
+    const { api, modal, session } = this
     const { Component, pageProps = {} } = this.props
     return (
       <>
         <Container>
-          <Provider value={{ api, router, session }}>
+          <Provider value={{ api, modal, router, session }}>
             <Component {...pageProps}/>
           </Provider>
         </Container>
diff --git a/client/pages/index.jsx b/client/pages/index.jsx
index 6e80525..9286d77 100644
--- a/client/pages/index.jsx
+++ b/client/pages/index.jsx
@@ -1,15 +1,8 @@
 import { authorize } from '../lib'
-import { Consumer } from '../services'
 
 export default function Index() {
   return (
-    <Consumer>
-      { value => {
-        // eslint-disable-next-line no-console
-        console.log(Object.keys(value))
-        return <h1>Hello, World!</h1>
-      }}
-    </Consumer>
+    <h1>Hello, World!</h1>
   )
 }
 
diff --git a/client/pages/login.jsx b/client/pages/login.jsx
index d7c986c..8c18286 100644
--- a/client/pages/login.jsx
+++ b/client/pages/login.jsx
@@ -31,3 +31,10 @@ export default function Login() {
     </Container>
   )
 }
+
+Login.getInitialProps = ({ res, router, isServer, session }) => {
+  if (!session.user) return
+  isServer
+    ? res.redirect('/')
+    : router.replace('/')
+}
diff --git a/client/services/context.jsx b/client/services/context.jsx
index 662d91c..d6956df 100644
--- a/client/services/context.jsx
+++ b/client/services/context.jsx
@@ -3,7 +3,7 @@ import getDisplayName from 'react-display-name'
 
 export const { Provider, Consumer } = createContext({})
 
-export const withServices = (Component, pickServices) => {
+export const withServices = (Component, selectServices) => {
   return class WithServices extends PureComponent {
     static displayName = `WithServices(${getDisplayName(Component)})`
     services = null
@@ -11,9 +11,9 @@ export const withServices = (Component, pickServices) => {
       return (
         <Consumer>
           { services => {
-            this.services = this.services || pickServices(services)
+            this.services = this.services || selectServices(services)
             return (
-              <Component services={this.services} {...this.props} />
+              <Component {...this.services} {...this.props} />
             )
           }}
         </Consumer>
diff --git a/client/services/index.js b/client/services/index.js
index 9b7a539..35eb87c 100644
--- a/client/services/index.js
+++ b/client/services/index.js
@@ -1,3 +1,4 @@
 export * from './context'
 export { default as initApi } from './api'
+export { default as initModal } from './modal'
 export { default as initSession } from './session'
diff --git a/client/services/modal.js b/client/services/modal.js
new file mode 100644
index 0000000..8ddaf93
--- /dev/null
+++ b/client/services/modal.js
@@ -0,0 +1,36 @@
+import noop from 'lodash/noop'
+import { Model, isServer } from '../lib'
+
+class Modal extends Model {
+  get init() {
+    return {
+      onClose: noop,
+      isOpen: false,
+      render: noop
+    }
+  }
+  get render() {
+    return this._model.render
+  }
+  open({ onClose = noop, render = noop }) {
+    if (this._model.isOpen) return
+    this.update({
+      isOpen: true,
+      onClose,
+      render
+    })
+  }
+  close(response) {
+    if (!this._model.isOpen) return
+    this._model.onClose(response)
+    this.update(this.init)
+  }
+}
+
+let modal
+
+export default function initModal() {
+  if (isServer) return new Modal()
+  modal = modal || new Modal()
+  return modal
+}