Problem: Continue the following story.

The young magician was able to lock the assistant in the box but couldn't use the key to open it because the 
Here's how I want to continue it: box was fine.

Problem: Continue the following story.

Samuel was always given terrible service compared to Justin, by reason of 
Here's how I want to continue it: Samuel being a rude person.

Problem: Continue the following story.

The athlete had to prepare for the final competition with his uniform but not his helmet because the 
Here's how I want to continue it:
helmet was stuck in the locker.