Milly, Aubrey and Jonah Story have been invited to spend the summer on Gull Cove Island by their grandmother, Mildred. That might not be an out-of-the-ordinary invitation for some people, but it is for these three teens. For one thing, they’ve never met their grandmother. For another, they haven’t seen each other for years and their parents (Milly’s mom and Aubrey and Jonah’s dads) are also estranged. So, it’s a weird request all-around.

Gull Cove Island was a little-known haven for artists and hippies when Abraham Story turned it into what it is today: a place where rich and semifamous people spend ridiculous amounts of money pretending they’re getting back to nature.

Milly’s mother, Allison, is anxious for her daughter to go. Twenty four years ago, she and her brothers (Adam, Anders and Archer) had each received a letter from their mother which said “You know what you did.” With that, they were cut out of their mother’s life both personally and financially and none of them really understood why. Milly’s mom thinks this invitation may be the opportunity to mend fences and for the cousins to get to know each other.

This is the set up for Karen M. McManus (One of Us is Lying, One of Us is Next) latest novel The Cousins. The novel is told from multiple perspectives during two different time-lines, so you get to see the parents as young adults and then their offspring who arrive on Gull Cove Island to a less-than-warm reception. Clearly there is something strange going on, and Milly is determined to figure it out, with or without her cousins’ help.

Like her previous novels, McManus manages to keep all the plates of a compelling mystery spinning. Each of the three teens are intelligent and likeable. The real mystery is rooted deep in their parents’ past and some of those characters aren’t so nice, particularly Jonah and Aubrey’s dads. Readers will have a lot of fun trying to figure out what the heck is going on, but like with her previous novels, McManus will always be one step ahead of you.