Varrock Castle

• To retrieve the second Silverlight key, you must go through the kitchen in the Varrock Castle. Walk outside, to the courtyard, and locate the drain. It is located to the left of the exit.
  
  

The Drain

• Fill a bucket with water. If you do not have a bucket, you can find one on the second floor, directly above the kitchen. Use the bucket of water on the drain. The key will drop into the Varrock sewers.
  
  

The Silverlight Key

• Go east, out of the castle's courtyard, and enter the dungeon. Take the first path to the left. The key is located at the top of the path.