The X-Files: Plus One Season 11, Ep 3
A spate of deaths in which victims are plagued by their own doppelgangers leads Mulder and Scully to a pair of twins playing a dangerous game. Mulder, to Scully: "you and I are gonna jump on I-95 South this morning and get back to our bread and butter." [Yes, it's a Monster of the Week episode!] [more inside]
Elementary: Tag, You're Me Season 4, Ep 3
Holmes and Watson are back with the NYPD, just like that. Their first case back is about two dead men who look remarkably alike, which leads to a recently thawed cold missing person case and a tech company that specializes on facial recognition. And Sherlock's father, Morland, is still in New York for reasons not wholly clear (yet).