It's Thanksgiving and McGarrett and the rest of the crew are playing football until McGarrett had to rush back to his home where his sister forgot to unthaw the turkey. The doorbell rings and in comes McGarrett's Aunt Deb (Carol Burnett), who unexpectedly visits them. Meanwhile, Chin is on the phone with Kono and it is revealed that Adam might be hiding in Seattle and she is on her way over there to check. Five-0 is tasked in a murder where the body was badly decomposing; it is revealed to be one of the Secret Service. Despite being a huge target, the President is coming to Hawaii on a mission and cannot cancel. Five-0 races against time to stop the assassin. Elsewhere, Aunt Deb gets arrested and reveals to McGarrett she has terminal brain cancer and will not seek treatment. It turns out the assassin's target wasn't the President but a person from his past. Five-0 finally catches and kills him. Later that night the crew head to a restaurant to celebrate Thanksgiving and Aunt Deb sings to McGarrett and Mary to create some lasting memories.