Gravity was a bit of a change from Tess Gerritsen's normal style. She tends towards medical thrillers (and excellent ones at that), whilst this book focuses on a space mission aboard the ISS. Young researcher Emma heads off for her first mission, replacing a member of the previous team who's been taken ill. But then other teammates start to get sick, and strange things are happening to the mice on board...

Honestly, I didn't find this quite as gripping as the majority of her books, but it's still worth a read.