In a short-staffed New York City hospital, scores of cops and attorneys are quarantined from maintaining law and order when they report hearing a clanging metallic chord every time they travel to a new location.

Young Sookie Stanhouse patiently waits to give blood in the crowded lobby. In the ER, visiting volunteers Drs. Gregory House and Addison Montgomery greet a frantic Cesare Borgia, whose bodyguard Tyrion Lannister has a spear sticking out his back.

“They’ve stolen the pope’s miter — the triple crown!” Borgia gasps. (Chester “Ace” Bernstein’s ears prick up at the mention of the triple crown, but he’s out of luck.)

House pushes Lannister’s spear in deeper and tells him to suck it up. Borgia’s media rep Don Draper lights up a cigarette, setting off the sprinklers as the lights go out. When lights are restored, Dr. House is discovered lying dead on the ER floor with two bloody puncture wounds in his neck.

“This is supernatural!” announce FBI agents Axl Rose and Mick Jagger, who are quickly exposed as impostors Sam and Dean Winchester.

As they run away, U.S. Marshal Raylan Givens pulls out his Glock semi-auto and takes them out, murmuring “Ah wuz justified” and melting into the night. International terrorism is suspected in the theft, and CIA agent Carrie Mathison is called in, but she immediately clashes with Det. Olivia Morgan and a catfight ensues. Happening by, Det. Jane Rizzoli and medical examiner Maura Isles jump into the fight for the heck of it. In all the excitement, Sookie vanishes.

With approximately 7,836,419 people having a motive to kill House, extra detectives are put on the case. Visiting from Hawaii, Steve McGarrett and Danny Williams are attending a Broadway musical about Marilyn Monroe when the lead’s wig falls off, revealing Sherlock Holmes in disguise. (McGarrett whispers to his buddy, “Libretto ‘im, Danno.”)

Jim Moriarty stands up in his box seat to shoot his nemesis, but the bullet goes wide and grazes a chorus boy (guest star Neil Patrick Harris). A car chase ensues. When the car hits a pole, the trunk pops open and the pope’s miter bounces out onto the street. It’s retrieved by Nucky Thompson, who spirits it off to Atlantic City, where it’s never seen again.

On a tip from mentalist Patrick Jane, Dexter Morgan is arrested for House’s murder. He hires Patty Hewes and Alicia Florrick as his counsels, with Jack McCoy coming out of retirement to prosecute the case. Surprise witness Nurse Jackie Peyton testifies she saw Dr. Derek “McDreamy” Shepherd offering cash to vampire sheriff Eric Northman in the lobby. A skeptical Judge Randy Jackson snorts, “You’re out of order, dawg. And pitchy.”

But under dogged questioning, Sheriff Northman admits he was hired to give a revenge bite to Shepherd’s ex Dr. Montgomery. Unfortunately, he was wearing Miami detective Horatio Caine’s sunglasses in the ER and chomped on House by mistake. The vampire turns into a bat upon being declared a flight risk.

In the courtroom, the Dowager Countess of Grantham stands up and announces that Dexter is the long lost heir of Downton Abbey. Taking him by the hand, she brushes asides objections that he’s a serial killer.

“My deah, all the best are,” she drawls.

In an epilogue, a van pulls up to Alcatraz Prison, where three inmates see McDreamy arrive in handcuffs and grin with anticipation. Dissolve to Dr. Bob Hartley waking up in bed, water running in the bathroom. He muses, “I just had the strangest nightmare. . .” Bobby Ewing steps out of the shower and slips into bed, and we fade out on Dr. Hartley’s horrified closeup.