To the trilogy and beyond...
It's all over for the ogre.
This week sees the UK release of Shrek Forever After - the fourth full-length film that brings to an end the adventures of the green giant, Donkey, Fiona and Puss in Boots.
The film has taken some $230m (£154m) since its release at the North American box office, making it one of the top five most successful films of the year so far.
Crucially, the fourth movie has managed to retain its A-list voice cast which was in place at the beginning. It's also in 3D.
Not all film franchises have it so good. There are many with a "4" after the title that go straight to DVD, with the talent that helped bring success to the first film long since departed.
Why do "four-quels" get made? Is it just about money?
"The only reason to go back is commercial," says the author and critic Kim Newman.
"Shrek is unfortunate in that the original had a start which ends - all the sequels have had the problem of going back and trying to make a film about the reformed Shrek."
Newman adds: "Nobody makes a sequel to A Christmas Carol because you don't want Ebenezer Scrooge to be a nice old guy who loves Christmas and gives away a free goose to the kids."
Some film characters - like Tarzan, Dracula or James Bond - have gone beyond the law of diminishing returns often associated with sequels.
"You get past the first four or five it's no longer a question whether one is better than the next - they just go up and down," points out Newman.
"That said," he adds. "Thunderball wasn't as good as Goldfinger."
Asked for a really bad example of a "four-quel", Newman doesn't hesitate: Omen IV - The Awakening.
"It was a trilogy that ended and then they stuck another one on the end - people often forget it even exists. Some of the DVD box sets try not to include it!"
But it's not all bad news for fourth films. Newman credits the fourth Final Destination film as being "a bit better than the previous sequels".
Here's a look at some well-known - and less well-known - film franchises that have made it to fourth base.
The story: Ellen Ripley (Sigourney Weaver) killed herself at the end of Alien 3, so she's back here as a clone. Scientists have grown an Alien queen from an embryo. You can guess the rest.
When? The fourth Alien movie arrived in November 1997, more than five years after David Fincher's Alien 3.
Worth the wait? Critics were largely split. Delicatessen director Jean-Pierre Jeunet brought a distinctive visual style, but it was hard to top the high benchmark set by Ridley Scott's Alien (1979) and James Cameron's Aliens (1986).
Sample review: "It brings a mordant, crackerjack wit to the world of chest-busting, head-ripping creepazoids from beyond." Stephen Hunter - The Washington Post
The next chapter? The Alien franchise joined up with the Predator franchise. Ridley Scott is working on on two 3D Alien prequels.
Carry On Constable
The story: Bumbling new police recruits cause havoc on the beat.
When? 1960, following on from 1959's Carry On Teacher.
Worth the wait? Still early days in the long-running Carry On series, this marked the first ever appearance of Sid James. The golden era of the Carry On films - like Cleo and Screaming - was still a few years away.
The next chapter? The series carried on regardless the following year, with Carry On Regardless.
Conquest of the Planet of the Apes
The story: Caesar (Roddy McDowall) leads an ape revolt against the humans who have enslaved them.
When? The film came a year after 1971's Escape from the Planet of the Apes.
Worth the wait? Set several years after the previous entry, Conquest was violent and bleak, but kept the series alive.
Sample review: "J Lee Thompson's direction furiously propels the action in a compact chromium-and-glass setting - and wait till you see that last battle royal." Howard Thompson - New York Times
The next chapter? 1973's Battle for the Planet of the Apes was the final entry in the film series - before Planet of the Apes was "re-imagined" by Tim Burton in 2001. Andy Serkis has been cast as Caesar in Planet Of The Apes prequel Rise Of The Apes, due out in 2011.
Harry Potter and the Goblet of Fire
The story: Now in his fourth year at Hogwarts, Harry (Daniel Radcliffe) attends the Quidditch World Cup, competes in the Triwizard tournament and crosses wands with Lord Voldemort.
When? The fourth Potter film was released in November 2005, 18 months after the popular instalment Prisoner of Azkaban.
Worth the wait? Mike Newell's Goblet of Fire was the most successful film of 2005 in the UK, beating Star Wars III: Revenge of the Sith. The regular cast was joined by a new battalion of British acting talent, including David Tennant and Robert Pattinson.
Sample review: "It's refreshing that Potter 4 aspires to be a paranoid thriller rather than yet another detective mystery." Angie Errigo - Empire
The next chapter? Potter was back in July 2007 in Order of the Phoenix. And it's not over yet.
Indiana Jones and the Kingdom of the Crystal Skull
The story: Indy is back, and is on the trail of a skull that must be returned to a lost city in the Amazon which is guarded by the undead.
When? The film had its world premiere at the 61st Cannes Film Festival in May 2008 - 19 years after 1989's Indiana Jones and the Last Crusade.
Worth the wait? There was no major reinvention. Steven Spielberg stuck to the classic ingredients that had proved so successful in the three previous films. Reviews were largely positive.
Sample review: "Despite the genuine excitement, and one blinding flash of the old genius, this new Indy film looks like it's going through the motions." Peter Bradshaw - The Guardian
The next chapter? Nothing has been confirmed, but an idea for Indy 5 does appear to be in development.
Jaws - The Revenge
The story: A great white shark turns up to menace Ellen Brody (from the first two films) in the Bahamas.
When? This fourth film in the shark saga surfaced in July 1987 - four years after Jaws 3D.
Worth the wait? Lorraine Gary reprised her role as Ellen Brody. It didn't help - the critics gave this Jaws sequel a mauling.
Sample review: "Up until the ludicrous final sequence of the movie, the scariest creature in the film is an eel." Roger Ebert - Chicago Sun-Times
The next chapter? None, though genetically modified sharks turned up in 1999's Deep Blue Sea.
Leprechaun 4: In Space
The story: The gold-loving imp (Warwick Davis) kidnaps a princess and attempts to marry her as part of a plan to rule her home planet.
When? This direct-to-video comedy-horror came two years after 2005's direct-to-video Leprechaun 3. The first Leprechaun film appeared in cinemas in 1993 - featuring Jennifer Aniston in an early role.
Worth the wait? The consumer reviews are arguably more entertaining than the movie. The tagline suggests that nothing should be taken too seriously: "One small step for man... One giant leap of terror."
Sample review: "The best movie about a leprechaun in space I have seen in years..." Stefan Birgir Stefansson - sbs.is (via rottentomatoes.com)
The next chapter? Warwick Davis returned to the role in Leprechaun: In the Hood (2000). He was joined by Ice-T.