He made his first appearance in Genesis. He discovers that his adoptive sister Claire has powers However, he forgets this when his memory wiped. He is still living during the events of Four Months Later.
In Nothing to Hide Lyle discovers Claire's power when he finds the video cassette she made with Zach.
After Claire tells her father Lyle knows about her power Noah Bennet has a man he works with erase his memories, so claire is safe.
Later Lyle rediscovers Claire's secret and must deal with the consequences of having this knowledge.
Elle Bishop attacks Lyle at the Bennet home and later once Lyle has recovered he neutralizes Elle's power by throwing water on her.
To Be Added