How I Met Your Mother Exclusive First Look: How Barney Met His Father

An uncanny resemblance isn’t the only thing Barney Stinson’s long-lost father (played by John Lithgow) shares with Dexter‘s legendary Trinity Killer. “We started to get worried because there are some similarities to his character on Dexter,” reveals How I Met Your Mother cocreator Carter Bays, pointing out that much like Trinity, the elusive Jerome Whitaker “is a family man who lives in the suburbs.”

There’s one minor difference between the two, however: Jerome doesn’t, you know, murder people. “We took that out,” Bays deadpans. “He’s not going to be naked in the bathtub strangling someone.”

Bays calls Lithgow’s two-episode Mother stint — which kicks off March 21 (get an exclusive first look below) — the perfect post-Dexter “palate cleanser.” (This is the actor’s first TV role since leaving the Showtime smash two years ago.)

“John clearly wanted to do something that was just silly and fun — not that it’s all silly and fun because there’s a lot of drama to it — but something lighter and with more heart,” Bays adds. “We were honored that he chose us.”

Although hesitant to spoil too much about the long-awaited father-son reunion, Bays teases that Barney will struggle to “reconcile who he hoped his dad would be and who his dad actually is.”

The chemistry between Lithgow and Harris was predictably off the charts, says Bays. “They’re magnificent together. They’re both such great craftsman. We went down a long list of people we could possibly cast as Barney’s dad and as soon as we landed on John Lithgow something about it felt right.”