More than half a million pupils are attempting to solve a fictional crime as part of a project aimed at improving their scientific skills.
Is there a budding Sherlock Holmes in our midst?
The Planet Science Whodunnit provides children between the ages of eight and 14 with a forensics kit.
Classes conduct tests on mock crime scenes to discover which of a group of celebrities is guilty.
The suspects are singer Ms Dynamite, boy band Blazin' Squad, footballer James Beattie, BMX rider Zach Shaw and pop group S-Club.
On completion of the department for Education and Skills-backed investigation, classes can register their results on the Planet Science site be entered into a prize draw.
The "culprit" will be revealed in July and a "punishment" administered.
Planet Science will provide children with packs of "samples" from the fictional crime scene.
These include ink chromatography tests, which allow a note from to be compared with suspects' handwriting.
Fibres also undergo the forensic treatment, as do scrapings.
The initiative was the idea of Ruben Meerman, a physics graduate from Queensland University of Technology in Australia.
He has previously run a similar scheme involving 130,000 pupils in his own country.
Last month, the Save British Science Society said time and money pressures were reducing the capacity teachers of the subject to do their job properly.
It said staff had no opportunity to update their own knowledge of subjects, putting students at a disadvantage.
Practical classes had also been cancelled because of difficulties and huge costs involved in excluding disruptive pupils, who might have posed a danger to others during experiments.
SBSS director Dr Peter Cotgreave said: "Teachers are pretty demoralised about the state of the profession at the moment."