You’ve probably seen viral videos claiming some medical breakthrough and cleverly titled “Use this weird trick to cure [insert ailment]”. People seem to find this teaser title irresistible. Jonathan Jarry and colleagues at McGill University’s Office for Science and Society use a similar title for a video that has a surprising twist in store for gullible viewers: “This natural trick can cure your cancer”.

The video initially claims to present a cure for cancer based on a species of moss (Funariidae karkinolytae), that has been known since the 1800s. The reason you’ve not heard about it, the video claims, is because the knowledge has been suppressed by pharmaceutical companies. The video then shows an old, black and white photograph of a Dr. Johan R. Tarjany, who looks very professorial in his three-piece suit and bow tie, and describes him as the discoverer of the moss’s cancer-killing trait. The video then goes on to tell the story of the moss and how it kills cancer cells by altering their DNA. And, of course, Dr. Tarjany added the moss to his diet and guess what? He never developed cancer.

At this point, the viewer is probably impressed with Dr. Tarjany and his discovery. Except there is no Dr. Tarjany and everything so far presented is untrue. In the remaining minute, the video deconstructs the claims it made earlier about Dr. Tarjany and the cancer-killing moss. In the process, the video’s creators provide a blueprint for viewers to follow when confronted by such a claim–how to evaluate the “evidence” and look for inconsistencies in the “facts” presented.

In just a couple of minutes, this video shows how viewers can be fooled into believing a pseudoscientific idea and how to avoid it–and did it in a way that was entertaining. Using the pseudoscience playbook to make the video was particularly clever and effective. Check it out below (the comments are also interesting–see the link to YouTube):