In Hong Kong, Peru and Madagascar people are being infected with a deadly alien virus that leaves them transforming into grotesque statues before shattering into dust. As per the stinger at the end of the previous episode the Doctor is already aware of these bizarre deaths.
With the TARDIS team split into three groups, Yaz (Mandip Gill) and Graham (Bradley Walsh) trace a mysterious alien reading to Hong Kong, where they meet British former-cop Jake (Warren Brown), who is searching the area for his missing husband.
Elsewhere, in Peru, Ryan (Tosin Cole) assists a travel vlogger (Joana Borja) whose friend has mysteriously disappeared. Whilst, the Doctor pops up near a mobile laboratory on a beach in Madagascar.
Both witness the gruesome and sudden death of a person infected with this deadly virus, named per the episode’s title, Praxeus.
With the help of the tech in the lab the Doctor discovers this alien virus is attracted to plastics. This is where the episode becomes somewhat confusing. In a scene filled with exposition dump and scientific jargon the alien virus seems to consume plastic particles.
Originally held in a host species of birds, who consume plastics from the ocean, it is deadly once contracted by humans, who carry micro-plastics in their biology.
This idea plays with real world science, how influenza is contracted by jumping from animal species over to humans, and makes a statement about global plastic pollution.
Whilst not as preachy as Orphan 55’s shoehorned speech about being eco-friendly, this element of the story does work to provide thought-provoking commentary on the widespread problem of plastic.
Somehow the Doctor manages to figure out a cure, first testing it on Jake’s sick husband Adam (Matthew McNulty). But in order to stop the global threat of the virus broader action needs to be taken.
After discovering that a humanoid species has been ravished by the virus on their home planet, they came to Earth to run experiments to establish a cure. Using Earth’s animal and human populations as a giant petri-dish.
Upon discovering their ship, the Doctor discovers that placing the cure in the engines and setting them to detonate in the Earth’s atmosphere will destroy the virus in the birds.
However, the automatic controls for piloting the ship are broken leading Jake to make a heroic sacrifice to pilot the ship manually. Luckily, though the episode avoids conforming to the predictable ‘Kill your gays’ trope and instead the Doctor is able to save Jake at the last second in an appropriate heroic move.
This episode saw yet another Earth-based story unfold, and whilst intrigued with mystery it may not be as exciting on rewatch. Whilst the most of the supporting characters had something to do, others were either forgettable or unlikable.
However, splitting up the companions and the Doctor gave them all something interesting and worthwhile to do, it’s just a shame that doesn’t happen often when all four of them are together.
What would understandably be a less-riveting episode than last week’s shock-filled Fugitive of the Judoon, this was still a solid hour of television with the message of human connectivity.