Two heads are much better than one when it comes to untangling television's most complex criminal activity - especially when there's a dash of chemistry going on as well. Here are four of our favourite detective duos...
JONATHAN CREEK AND MADDY MAGELLAN
Duffel-coated, magic-making super-sleuth Jonathan Creek has had a few different partners over the years, but most fans will probably agree that the Jonathan and Maddy team-up is the most iconic. And with good reason: the contrast between the shuffling, nerdy genius and the gobby, pushy, incredulous journalist is pure bliss to watch, and a nicely down-to-earth counterbalance to the warped and impossible crimes they investigate.
True, Maddy can be rather... cutting towards Jonathan. Calling him a "spineless cretin" is about as close as she gets to paying him a compliment. And even though there's undeniable attraction (much as they would probably try to deny it in the early days), it's fair to say their bedroom frolics left a bit to be desired. She compared it to sleeping with an uncle, which is right up there in any list of things no man wants to hear from a woman he's just slept with. It's just a good thing they're such great mates. Kind of.
KATE WARNE AND WILL PINKERTON
In 1860s Kansas City, women are expected to either be good wives or sultry saloon wenches. So it's no surprise the local menfolk are baffled at the presence of Kate Warne, who is neither. The Pinkertons' Kate is a young lady with the audacity to have a "masculine" job (private eye) and a sharp mind (chemistry and ballistics are among her specialties). One of the locals who finds it all a bit strange just happens to be her partner in crime-fighting, Will Pinkerton.
A handsome rogue who's used to charming women with a wink and a smirk, Will meets his match in Kate, whose wit and one-liners soon put him into place. Despite Will's early irritation at having to work with - shock - a woman, they prove a formidable team and have always got each other's backs, whether they're going undercover, riding across the plains, or having the occasional gunfight with grizzled cowboy types.
PETER BOYD AND GRACE FOLEY
No, Boyd and Foley aren't technically a double act, being only two members of the wider Waking The Dead ensemble. But they're very definitely a partnership unto themselves, which is a good thing because the furious and fiery Peter Boyd would likely have got himself fired or even arrested without the lovely and long-suffering Grace Foley there to soothe and talk sense into him.
There's something incredibly touching about their relationship - Grace is like the older sister or teacher or shrink or nanny (tick as appropriate) who tries her best to keep Boyd's reckless nature in check. No easy thing, given how the smallest upset in a case tends to have Boyd bellowing at his underlings and threatening to beat up the suspects. You've also got to love the way they often digress into oddly profound chats on morality, philosophy and history. Certainly makes a change from the usual office chit-chat.
THOMAS LYNLEY AND BARBARA HAVERS
The whole idea of a "chalk and cheese" pairing is taken to extremes in Inspector Lynley Mysteries. If it wasn't for the fact they're both coppers, these are two people who'd probably never have crossed paths, because they hail from different worlds. Thomas Lynley is a suave member of the upper classes - the 8th Earl of Asherton, in fact - who spends his spare time riding horses, guffawing with former public schoolboys, and hobnobbing with royals.
Barbara Havers, on the other hand, has had to fight her way up from a humble background, and doesn't take kindly to Lynley's uber-privileged background. "An arrogant aristocratic ponce," is her initial take on him. Still, despite the tension between the pair, they do bring out the best in each other, and the slow flowering of their friendship is one of the pleasures of seeing them at work.
Watch The Pinkertons Sundays at 8pm on Drama.