Just seven of the most insanely ridiculous story lines from Grey's Anatomy.

SPOILER WARNING: If you haven’t watched up to season 14 episode two, we suggest you stop reading. (And search for this story again when you’re all caught up.)

Grey’s Anatomy is coming up to its 300th episode this month, and while the medical drama hasn’t gotten this far without a talented cast and a team of great screenwriters, there’s been the odd shark-jumping episode or two.

So let’s take a look at the most ridiculous plots ever to face the surgeons at Seattle Grace.

When we found out Meredith had ANOTHER secret sister

Meredith was not at all happy when her half-sister Lexie Grey showed up at Seattle Grace and tried to bond with her, but eventually, she did. And then she died. Maybe that’s why the writers decided to introduce a second secret sister for Meredith in the form of Maggie Pierce? But what’s more ridiculous than Thatcher Grey having another child is the fact that she also became a top-class surgeon. Clearly, there are no other career paths for the Grey kids.

Meredith wasn't the only character to have long lost family members show up out of the blue. Andrew DeLuca's sister Carina appeared at the start of season 14 to research female orgasms (because of course, she is also a doctor). And then there was that time Owen Hunt's sister Megan came to the hospital after being missing in a warzone for 10 years.

When Dr Derek Shepherd - AKA McDreamy - um, died

No character death (with the exception of Patrick from Offspring) has been more upsetting than the death of Dr McDreamy.

The car accident scenario was over-the-top enough (a semi ploughing into his parked car after he just rescued a bunch of people) but we had to watch as a voice over of brain-dead Derek told doctors it was too late to save him in this sad, slow death that ended with Meredith turning off his life support.

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When Meredith had three kids that we basically never saw

Speaking of Meredith and Derek, remember those three kids they had? Zola, Derek and Ellis (conceived on the day he died)? If you don't, don't worry, they are barely ever on screen anymore.

When they killed Denny, but would not let him die

A result of Denny's tragic death was the $8.7 million Izzie inherited from him - enough to open her own free clinic. The show wasn't done with Denny though - and brought him back as a ghost, who she had loud, passionate sex with and ended up signifying Izzie's brain tumour.

Denny also appeared as a sort-of ghost to Meredith after she almost drowned in a ferry accident - along with Dylan - the man who died in the bomb episode in season two. We're meant to believe Meredith is in some sort of afterlife or limbo, before she is revived.

When they did a musical episode

Season seven's "Song Beneath the Song" begins with Arizona Robbins proposing to Callie Torres right before they are in a car crash. And while the rest of the episode Callie is fighting for her life, and that of her unborn baby, what most fans remember about the show is the singing.

Yes, it seems every long-running TV show decides to do a musical episode at some point and it almost always leaves fans asking "WTF?"

When George died

For a show about saving lives, there were a hell of a lot of main character deaths. An especially memorable (and heartwrenching) was George O’Malley's at the very start of the sixth season. George was hit by a bus while trying to save a woman, and, adding insult to injury, was mangled so badly he wasn't identifiable until minutes before his death.

When two characters died in a plane crash

Like I said, a lot of people died. Not happy with just the one character being killed in a plane crash which happened at the end of season eight, this time the writers decided to kill off Lexie Grey and Mark Sloan, while seriously injuring Arizona and Derek. Morbid.

Fellow Grey's fans, did we miss anything?