A man is fatally hit by a speeding truck, and he turns out to be a hired hitman assigned to take down Lt. Commander Geoffrey Shoup. Shoup is a high-ranking committee member who has garnered a few enemies during his time on Capitol Hill. NCIS is assigned to protect Shoup, and Ziva is charged to keep an eye on him.
The hitman's bank account had $25,000 deposited to it, from the account of a man named George Kaplan. An accountant, Drew Turner, wired the money under Kaplan's name, but claims that she doesn't know anything about Shoup. Later, Turner is found dead in an apparent suicide. However, Ducky figures out that she'd been murdered and then the suicide scene was staged afterwards.
Shoup was actually receiving money from a foreign shipbuilder in exchange for giving them contracts with the US government. Shoup and Turner created the Kaplan account to launder the cash. But Turner wanted all the money and hired someone to take out Shoup so that she'd be able to fund her gambling.
Meanwhile, Abby has come up as a match on the kidney donors list, and she finds out that the only other match shares familial DNA. The man is her brother. She doesn't think her parents would have ever put anyone up for adoption, but she suspects that they would be willing to adopt. She tests the DNA of the lock of her mother's hair she keeps with her and finds out that they're not biologically related. She doesn't wish to burden her newly-found older brother with the news that he has a sister until he's finished with surgery and recovered. But what else should she do with the news?