|First appearance||The White Mountains|
|Portrayed by||Michael Gilmour|
Jack Leeper is a cousin and friend of Will who was one year older than him and was thus capped one year before Will's due capping. The change in Jack's personality after capping was one of the important factors that made Will start his journey to freedom.
Jack was a good friend of Will and the two used to go to different places together and talk. When Jack became of age, he was capped by a Tripod. As with most capped people, Jack's personality was changed and became more docile and duty-oriented. Will took notice of this and started to have doubts about the rightness of capping.
Not much is known about Jack's personality, except that he was generally friendly and curious before being capped.
- The White Mountains (First appearance)
- The City of Gold and Lead (Mentioned only)
- The Pool of Fire (Mentioned only)