The goal of any great TV show, whether it's a fun little sitcom, a bracing crime procedural or a fantastical epic, is to keep its audience on its toes. Basically, to surprise and keep us guessing, and to push the boundaries of its plot, tone or genre.
After all, the making of any TV show, regardless of quality, is a tough business, and if you want your project to stay alive before an untimely cancellation, you've sometimes got to push yourself to do something new and daring for those watching at home.
And nine times out of ten, this kind of narrative twist can work wonders. Unfortunately, taking a leap of creative faith can also painfully backfire, or at the very least leave audiences shaken to the core regarding what they've just been subjected to.
Such is the case with the following 10 shows, which in a single scene - for better or worse in the long run - took things a little bit too far, and left fans and critics alike disgusted and uncomfortable.
That's not to say these scenes are bad - a couple are actually very good, even necessary - but the way they're presented sure doesn't leave you wanting to hit rewind...
10. Izzie's Ghostly Grief - Grey's Anatomy
Grey's Anatomy has a long history of slightly odd storylines, mainly where its unlikely medical cases are concerned (remember the guy who ate dolls?), but the series was never stranger than when surgical resident Izzie Stevens (Katherine Heigl) started hallucinating and even sleeping with the ghost of her late ex, Denny (Jeffrey Dean Morgan).
Now, this subplot as a whole isn't as bad as you might remember, serving as a powerful if jarring exploration of grief and mourning since Izzie blames herself for Denny's death and is seeing him because of the cancer she's yet to be diagnosed with, but the length of it and its unsettling intimacy is far too odd to be as moving as it wants to be.
Credit should go to Heigl and Morgan for giving such a mismatched storyline the depth they did, but Grey's Anatomy fans the world over will all likely agree this reunion never should have happened. But hey, when a series has run for as long as this cult favourite has, you're bound to have some duds.