Alison Bergeron has her doubts about hosting a birthday party for her twin stepdaughters, seeing as it'll include all of her new husband's ex-in-laws. Still, she's a good sport, and everyone has a great time, especially the girls, who receive $10,000 from their estranged uncle, Chick. The girls' father, NYPD Detective Bobby Crawford, and Christine, his ex, think the gift is too much. When Crawford swings by Chick's apartment to return it, he finds Chick dead, with roughly $250,000 stuffed in his mattress. The death is ruled a suicide, but Christine isn't convinced, and even Alison can't help but admit that there must be a lot more to Chick's death than meets the eye. Extra Credit, the latest in Maggie Barbieri's stellar Murder 101 series, finds Alison and Bobby delving into family secrets they'd both rather leave untouched.