8 June 2023. A shark attacks a 23-year-old Russian man swimming just metres from the beach in the Red Sea vacation resort of Hurghada, Egypt. Horrified tourists watch from the shore. His injuries are so severe that he dies before help can arrive. Within hours, videos of the attack spread on social media. It comes less than a year after two women were killed by sharks in the space of two days on the same stretch of coast. A spate of killings like this is unprecedented in the Red Sea.

What brought these sharks into the shallow waters of luxury holiday resorts, away from their natural hunting grounds in the open ocean? Could mounting pressure from humans – fishing, tourism and man-made climate change – be altering how these apex predators live and hunt?

An innovative mix of current affairs investigation and scientific analysis, this documentary explores what could have caused not just the attacks in the Red Sea, but also other recent unusual shark encounters around the world, including in the waters off Sydney and Florida.

Striking CGI reveals the fearsome physiology and behaviour of these creatures close-up, by exploring the ‘modus operandi’ of these ferocious predators – from how their powerful jaws work to the way their giant livers store immense energy reserves to help them survive long periods between meals.

Professor Gavin Naylor from the University of Florida delves into the evolution of sharks and the reasons why Florida and Australia are two of the world’s hotspots for attacks. His associate, Dr Dean Grubbs of Florida State University, gets hands on, catching sharks in Florida’s Gulf Coast to better understand their movements and population dynamics.

In Big Grassy Island, Florida, 18-year-old shark attack survivor Addison Bethea recounts a brutal encounter with a shark in 2022. She was swimming in shallow waters looking for scallops with her firefighter brother Rhett, when a shark grabbed her and pulled her under the water. With remarkable bravery, Rhett fought the shark off and saved his sister’s life. But Addison’s severe injuries meant her leg had to be amputated. This was the first recorded shark bite in these waters, and experts are interested in what could have caused it.

In Sydney, Dr Laura Ryan from Macquarie University is researching whether great white sharks might be attacking people in a case of mistaken identity, where they confuse swimmers and surfers with their preferred prey of seals.

And marine ecologist Dr Lucy Hawkes from the University of Exeter, who was the first scientist to catch and tag a silvertip shark in the Red Sea, provides a devastating picture of how shark populations are declining in many areas.