Peter Capaldi

The Doctor

Alex Kingston

River Song

Greg Davies

King Hydroflax

Matt Lucas

Nardole

Phillip Rhys

Ramone

Rowan Polonski

Flemming

Robert Curtis

Scratch

Anthony Cozens

Concierge

Chris Lew Kum Hoi

Alphonse

Nicolle Smartt

Receptionist

Liam Cook

King Hydroflax's Body

Nonso Anozie

Voice of Hydroflax (voice)

Clem So

Starline Galactic Villain (uncredited)

William Hartnell

The Doctor (1) (picture) (uncredited)

Patrick Troughton

The Doctor (2) (picture) (uncredited)

Douglas Mackinnon