Once we'd snapped out of our stunned state, we got to thinking - what are some of TV's greatest all-time plot twists? Read this week's Friday Fiver to find out what we ultimately landed on...
"We have to go baaaaaack!" - from Lost season three, episode 22/23, 'Through the Looking Glass'
Who can forget the cliffhanger ending to Lost's third season? The hit drama was turned on its head when scenes featuring a bearded Jack (Matthew Fox) - assumed to be flashbacks - were revealed as glimpses of the future, with he, Kate (Evangeline Lilly) and others having already left the mysterious island...
Bobby steps out of the shower - from Dallas season nine, episode 31, 'Blast From the Past'
One of TV's most famous twists and also one of the most derided, as the producers of Dallas decided to resurrect Patrick Duffy's deceased Bobby Ewing by revealing that his death - as well as the entirety of the previous season - had been conjured up in a dream by Bobby's wife Pam (Victoria Principal).
Cartman makes Scott Tenorman eat his own parents - from South Park season five, episode four, 'Scott Tenorman Must Die'
A 'comic' twist but one no less shocking than those offered up by more dramatic shows. In one of South Park's greatest ever episodes, Cartman is repeatedly humiliated by local bully Scott Tenorman, but ultimately gets his revenge in shocking fashion - having Scott's parents killed, chopped up and fed to their son as delicious chili.
Oh, and as if all that weren't enough, Cartman's arranged for Tenorman's favourite band Radiohead to visit South Park, but when they spot their biggest fan sobbing his eyes out, they brand him "the most uncool kid" they've ever seen. Ouch.
The President is the big villain! - from 24, season five, episode 16, 'Day 5: 10:00pm-11:00pm'
24 was another show that had its fair share of stunning plot twists, but surely this one has to come top? Until this shock reveal, we thought US President Charles Logan was simply a bumbling and ineffectual Commander-in-Chief - turns out he's neck-deep in a terrorist plot involving deadly nerve gas, the swine!
It's all been in Tommy's mind - from St. Elsewhere season six, episode 22, 'The Last One'
St. Elsewhere was a fairly standard medical drama that ran on NBC between 1982 and 1988, but the last ever episode ended on a doozy of a twist, hinting that the entirety of the show's six-year run had been dreamed up by the autistic Tommy Westphall (Chad Allen).
The only problem? A TV crossover between St. Elsewhere and Homicide: Life on the Street - plus crossovers that followed between Homicide and other shows - mean that series ranging from The X-Files to the entire Law & Order franchise may have all taken place solely in Tommy's mind too!
What are your favourite TV twists? Name some more shocking plot turns below!