The Great Barrier Reef is being devastated by a coral bleaching event caused by rising temperatures. How bad is it, what's being done and what can we do? We talk to James Kerry, project manager of the National Coral Bleaching Taskforce, to find out.

Speaking of symbiosis, we talk to Gregory Crocetti, one of the creators of the new graphic novel The Invisible War, about the life and death battle fought by bacteria inside an Australian nurse, while World War I rages around her. Find out more, read a free copy (if you're a schoolteacher) or pre-order a print copy via Pozible at theinvisiblewar.com.au.

Speaking of stories with a cast of thousands (or millions), who is the main character of the fantasy book and TV series Game of Thrones? Some mathematicians think they've figured it out, and they've published their results in a paper in the journal Math Horizons.