Doctor Who better prepare for a legen—wait for it—dary nemesis.

Neil Patrick Harris is joining the Whoniverse as part of the show’s 60th anniversary special, coming in 2023.

The How I Met Your Mother actor announced the news on Instagram June 13, revealing a photo of himself in character captioned: “My current gig. Never been more handsome. I am grateful to you, @russelltdavies63 for inviting me to join your Whoniverse. I’ll do my very best. This Doctor does not know what is in store. And even if he does…Who cares? Ha ha ha HA ha-ha-ha!”

Details about NPH’s character are scarce—and Doctor Who showrunner Russell T DaviesIt doesn’t help matters. 

Davies released a statement saying that “It’s a huge honor to open our studio doors in support of the great Neil Patrick Harris.” It’ll be interesting to watch. However, I can assure you that this stuff is not on the scale. Doctor beware!