Barney freaks out when Marshall bequeaths a slap bet slap to Ted and Robin. Meanwhile, Lily's estranged father shows up for Thanksgiving.
The BAU tracks a serial killer who chooses junkies, prostitutes and the homeless off the streets of Detroit as his victims.
Hours after calling Gibbs about a possible case, a Marine is found dead in Quantico; McGee and Bishop pose as a married couple.
Bull helps a famous social media influencer take her father to court to overturn his legal guardianship over her empire, which he was granted after the young mogul suffered a public mental breakdown.
As Kevin stresses about the premiere of his play, he receives support from an unexpected source. Randall struggles under the pressure of both his work and ailing father. Rebecca and Jack's Valentine's Day doesn't go as planned.