Our heroes are back... kind of.

First, the bad news: an ancient evil—you know, your standard consume-all-life-in-the-galaxy deal—is about to be unleashed. The good news? Squad 312 is standing by to save the day. They've just got to take care of a few small distractions first.

Like the clan of gremps who'd like to rearrange their favorite faces. And the cadre of illegit GIA agents with creepy flowers where their eyes used to be, who'll stop at nothing to get their hands on Auri. Then there's Kal's long-lost sister, who's not exactly happy to see her baby brother, and has a Syldrathi army at her back. With half the known galaxy on their tails, Squad 312 has never felt so wanted.

Shocking revelations, bank heists, mysterious gifts, inappropriately tight bodysuits, and an epic firefight will determine the fate of the Aurora Legion's most unforgettable heroes—and maybe the rest of the galaxy as well.

Once, a girl called Ace travelled the universe with the Doctor – until, in the wake of a terrible tragedy they parted company. Now, decades on, she is known as Dorothy McShane, the reclusive millionaire philanthropist who heads global organisation A Charitable Earth.

But Dorothy is haunted by terrible nightmares, vivid dreams that begin just as scores of young runaways are vanishing from the dark alleyways of London. Could the disappearances be linked to sightings of sinister creatures lurking in the city shadows? Why has an alien satellite entered a secret orbit around the Moon? Investigating the satellite with Ryan, Graham and Yaz, the Doctor is thrown together with Ace once more. Together they must unravel a malevolent plot that will cost thousands of lives.

But can the Doctor atone for her past incarnation’s behaviour – and how much must Ace sacrifice to win victory not only for herself, but for the Earth?