In Cycler, high school student Jill McTeague has a very unique medical problem.... for roughly four days a month, she turns into a boy. Basically, Jill herself completely disappears, and Jack is left in her place. Jack is anatomically, mentally, and emotionally male--a completely separate person from Jill.
Jill's parents, of course, are horrified by the situation. When Jack appears, Jill's mother locks him in Jill's room and refuses to let him have any contact with the outside world. And as soon as Jack morphs back into Jill, their mother leads Jill through a creepy meditation exercise and mantra of "I am all girl" to erase her memories of Jacktime. (But because Jack does not engage in the weird meditation, he can access all of Jill's memories.) Jill's parents have told the school that she has a "rare blood disease" to account for her monthly absences. No one else knows her secret, and for 24 days a month, Jill tries to live a normal life.
Because she has yielded so much to her super-controlling mother, that "normal life" is incredibly girly. One might assume that Jill would be consumed by feelings of worry, anxiety, or horror because of her condition, but no--all she thinks about are clothes and boys, and the ultimate pinnacle of both of those topics, prom. In particular, she and her two best friends spend all of their time plotting how Jill can win the attention of Tommy Knutson and convince him to ask her to prom.
Jack, on the other hand, is primarily obsessed with pornography. I also found this to be kind of ridiculous.... Really, if he only gets to live for four days out of every month and isn't allowed out of Jill's room, don't you think he'd be at least a little bit curious about the outside world? But no. Apparently the only topic that he has accessed from Jill's memories that interests him at all is Jill's best friend, Ramie. Jack is convinced that he is in love with Ramie, and for her, he tries to break free of the prison that Jill's mother has built for him.
I felt much the same about Cycler as I did about McLaughlin's Scored. Both had an awesome premise and the potential to develop into a fascinating story. But both fell back on heavy stereotypes for their characters, and the conclusions of each felt forced and way too brief. Cycler had the potential to be amazing, but in the end, it was just mediocre. That being said, I am still interested to find out what happens to Jack and Jill, so I do plan on reading the sequel, Re-Cycler. We'll see if that one leaves me with a better impression!