'Rachel McAdam's new horror comedy is bloody disgusting but incredibly enjoyable.'

Despite the blood-soaked movie poster, the suspense-filled trailer and the eerie film title, I still expected Send Help to be an entirely different movie.

In the wicked hands of the legendary director Sam Raimi, known for cult horror classics like The Evil Dead and Drag Me to Hell, and written by Friday The 13th duo Damian Shannon and Mark Swift, this (very) dark comedy has a surprise around every corner.

The story follows a beyond brilliant Rachel McAdams as Linda Liddle, a sheepish corporate researcher with a sharp mind (and secret obsession with Survivor) who is overlooked for a promised promotion by her firm's new nepo baby CEO.

Enter Dylan O'Brien as the arrogant, sexist and egocentric Bradley Preston, who treats Linda like an irritating mosquito he needs to swat away.

This brings us to Bradley inviting Linda on a business trip to Thailand as a consolation prize for crushing her hopes and dreams. Swell! On the way, their private jet crashes into the ocean during a tropical storm in a violent sequence that wouldn't be out of place in any Final Destination sequel. It's intense!

Watch the trailer. Post continues after video.

Linda and an injured Bradley are the sole survivors who wash up on a remote island.

The power dynamic between them is quickly flipped on its head when Bradley needs Linda's help with his recovery and basically everything because he's well, useless. Meanwhile, Linda has waited a lifetime to live out her Survivor fantasy.

"We're not in the office anymore," Linda tells Bradley, a line that shapes the direction of the rest of the film, where the real-world rules are thrown out the private plane's window.

What follows is a truly delightful narrative that completely subverts the viewers' expectations. At times, I fully expected this film to become a rom-com in the vein of Harrison Ford and Anne Heche's little island romance Six Days, Seven Nights.

Send Help deliberately leans into classic rom-com tropes, such as Linda nursing Bradley back to health, the two organising a dinner date night and a near-kiss after a near-death experience that bonds them.

Twist: they're in love??! Not so much! Image: 20th Century Studios.

This is genius because about halfway into the movie, the entire mood shifts between the two, as both of their sinister intentions start to boil to the surface.

The film quickly devolves into a hyper-violent horror movie where the line between simply surviving and reaping revenge becomes bloodily blurred.

The grossout moments, sharp satire and cultural criticism in this film have parallels to the Oscar-nominated, Triangle of Sadness, but delivered in a more accessible mainstream horror comedy that doesn't think it's smarter than the viewer.

Oh yeah, and this film is bloody disgusting at times (emphasis on 'bloody'), and viewers will need to have a high threshold to get through some of the scenes.

Whether it's the leads plunging thumbs into each other's eye sockets or ripping hair from their scalps, a hog vomiting blood or an amateur penis-related surgery — there is nothing sacred in this film, and nowhere director, Raimi, won't go.

And thankfully, most of these confronting scenes are in the hands of Rachel McAdams, who is ridiculously good in this. Bringing her comedic chops from Mean Girls, with the easy charm exuded Game Night, she nails the deranged Linda and delivers her most physically committed performance to date.

Image: 20th Century Studios.

Some might not buy casting McAdams as a dowdy outcast, given her Hollywood good looks, but she managed to pull it off. By choosing someone conventionally beautiful, this added a layer to the film as the audience was waiting to be shown the McAdams we know her to be.

In Send Help, McAdams lands some of the most laugh-out-loud dialogue of her whole career, and it was clear the actress was having as much fun making this as it was to watch.

Off the back of his impeccable double-role in Twinless, Dylan O'Brien gives another stellar performance as the guy you will love to hate. In a lesser actor's hands, Bradley could come across as cartoonishly villainous, but O'Brien delicately captures his vulnerable side, saving him from being someone you don't want to watch.

Given the isolated nature of this film, the cast is basically just McAdams and O'Brien, but I will give a mention to Australian actor, Xavier Samuel as Donovan, the incompetent, smarmy coworker given Linda's promotion. The actor's recent pivot to Disney-level supervillain (see: Netflix's Champagne Problems) is hilariously unexpected.

The only negatives of the movie were how often Raimi leaned on computer-generated graphics for shocks. This over-the-top digital animation might have added to the silliness of Drag Me To Hell, but it felt out of place in the natural landscape of a tropical island.

The two characters' motivations are a bit confused and convoluted at times, changing as quickly as the sea breeze shifts.

But these small misteps are all easily forgiven for a thoroughly original, unique movie that is straight-up hilarious — and also, you will likely never want to eat bacon again.

Feature image: 20th Century Studios.