It happened on the A6108 at around 4.35pm on Saturday (30 April 2022) and it involved a white BMW estate, a blue BMW, a grey Audi, a grey Mercedes Benz and a silver Suzuki car.
A woman passenger in the Audi car suffered serious leg injuries in the incident. She is receiving treatment at hospital.
Other drivers and passengers received treatment for minor injuries.
The road remained closed until 8.20pm while the emergency services worked at the scene and to allow a full collision investigation.
Officers would like to hear from anyone who saw the collision or recall seeing any of the vehicles prior to the incident, or motorists with any dash-cam footage that could assist with enquiries.
If you can help, please email email@example.com or call 101, option 2, and ask for Ben Prosser-Waite.
Please quote reference number 12220073181 when providing details