50-50 for Five

"I refuse to make friends with another cancer kid. There won't be a Five." "Five?" "Five people I've lost 'cause of cancer. Caroline was one; Monica, two; Gus, three." "And now Hazel's four." "Yes ma'am. So I want no Five." Three months after Hazel's death, Isaac returns to Support Group. There's no chance he'll get involved with anyone sick ever again. But then...there was Claire.