For Imogen, humans are nothing but a commodity, their lives mere obstacles to this monster empress who only wants to see her sister again.

Until one day in 1960s London…

Marceline Lydell is an up-and-coming biomedical engineer who has yet to make her prosthetic designs viable. When she finds herself trapped with a lemur-like creature–who is astounded by her work–she’s convinced she has just gone insane.

Now the future of both worlds hangs in her hands.

It was bad enough when only humans relied on her work. Now, she must work together with the otherworldly creatures around her, before Imogen realizes just how useful Marceline can really be in stopping the invading humans.