image copyrightHana Laurieimage captionGeorgia and Melissa were swimming in a lagoon in Mexico when the crocodile attacked

Like all horror stories, Georgia Laurie's started innocuously enough.

In a vibrant hostel in a tucked-away corner of Puerto Escondido, Mexico, Georgia now sits, freshly discharged from hospital, tapping on her phone and surrounded by fellow backpackers, trying to make sense of the past few days.

Certainly, it is the stuff of nightmares.

She and her twin sister, Melissa decided with a few friends to join a riverboat tour of the nearby Manialtepec Lagoon. It is a hauntingly beautiful place – a site of unspoilt natural beauty, its mangroves teem with Mexico's rich wildlife and birds.

However, its shallows are also the natural habitat for crocodiles, and unbeknown to the group, this is hatching season.

'It was fight or flight'

"I actually said to the guide, 'this looks like a place where crocodiles make their home'", Georgia told me with a wry smile. The bandage wrapped tightly around her wrist is evidence that she was right.

The guide – apparently a German national who was not registered with the tourism authority and has since fled – insisted it was safe to swim. As the group enjoyed a dip in the cool of the early afternoon (not a midnight swim as was initially reported), Melissa was suddenly tugged underwater.

"It was terrifying, wasn't it", Georgia says turning to other people in the group who were there, who nod in agreement.

image captionThe women's group were unaware the lagoon is a natural habitat for crocodiles

In what one local conservationist tells me was most likely a female crocodile defending its hatchlings, the animal went for Melissa on three separate occasions, puncturing her stomach and leg.

Yet rather than watch on helplessly, Georgia dived into action, punching the crocodile over and again on its nose.

"It was fight or flight", she remembers, "and you have to fight for the people you love".

Warning about rogue guides

One of the friends, Ani, scrambled onto the mangroves and called for help. A nearby boat with a different tour group, heard the cries and headed towards the commotion.

"I pushed through the undergrowth using my oar," says Lalo Escamilla, the boatman and local ornithologist who waded into the shallow waters to help the twins. Lalo took me to the site where the attack happened and explained that properly-trained boatmen like him are worried that the irresponsible actions of a rogue guide could harm their business.

"They're not guides", he says of the foreigners who live in Puerto Escondido and who round up tourists for cheap boat trips, undercutting the locals. "They're not federally-approved experts, they don't know this place. That's the problem."

media captionHana Laurie says her sisters were told the water was safe to swim in

Once on board, it was clear that Melissa's injuries were life-threatening. As well as the lacerations and deep cuts, there was water in her lungs and her wrist was broken. She would later develop sepsis from her ruptured intestine.

Such was the adrenaline pumping around Georgia's body, she didn't realise the extent of her own injuries until they reached a private hospital in the town.

"It wasn't until the nurse opened my fist to clean my hand that I realised that it had been slashed too," Georgia said. Understandably, all her focus had been on her twin sister, who by then had been placed into a medically-induced coma. Making the call to her parents was the next tough moment as it was around 04:00 in the UK.

"When they told me her condition was deteriorating, I had to let the family know."

image captionA local boatman, Lalo Escamilla, warns some tour guides know little about the region

Thankfully, Melissa has now emerged from the coma. After I sat and spoke to Georgia, she went to visit her sister in the hospital and says she is already looking stronger.

"We are all so happy," Georgia told me in a text.

However, the road to full recovery will be a long one. The Mexican doctors and the British Embassy have been "great", Georgia says. But Melissa must overcome her physical injuries and both women will need time to deal with the emotional and mental fallout of what they have been through. Georgia says she's struggling to sleep and that the images of the attack continue to crowd her thoughts.

What she can count on – at least until her family arrives in Mexico – is the spirit of camaraderie among the other travellers and backpackers she is with. Already they've formed a tight unit, a combination of friends from the UK, France, India and beyond who suddenly found one of their number under the full glare of the world's media for the most unlikely of situations.

The "hero twin sister" label isn't sitting comfortably with Georgia just yet. For now, she just wants a chance to recover from their horrific ordeal, and to breathe again after almost being dragged under for good.