Alexis ditched detention the day of the attach which saved her life. She later found out that her father was killed and her little brother was hanrnessed. When she found her mother she was very sick and eventually died.
The Skitters later found her with her ex-boyfriend Gregg and brought them to the Overlourds (and Karen). Thankfully Alexis manipulated them not to harness them, but to give them missions to help them. They agreed but, she had to do her work alone - and Gregg didn't have a mission. Her first mission included going to the 2nd Mass and bringing Ben back to them.