Fatal Flaw Fatal Series, Book 4.

The honeymoon's over, and now someone wants them dead... Back from their honeymoon, Senator Nick Cappuano and DC Police Lieutenant Sam Holland are ready for some normalcy after the whirlwind of their wedding, but someone has other plans for them. When Sam discovers wedding cards containing thinly veiled death threats, she's not sure if she or Nick is the target. Already on edge, Sam and her team start investigating a series of baffling murders...