DI Robbie Ross starts to feel the heat when Thomas Duffy, one of his informants, is brutally murdered, and the word 'grass' daubed in paint at the crime scene. Duffy's name appeared in Ross's contact book - which was stolen by a woman Ross took home with him. Ross knows he must speak up, but before he does, another name from the book turns up dead. Can he solve the case before his career becomes the next casualty?

When a law professor is accidentally stabbed to death in front of 30 trainee police officers during a training exercise it appears at first to be just a tragic accident. But when the team discover that the knife was tampered with, it soon turns into a murder enquiry. The team have 30 eye witnesses - but do the trainees really hold the key to solving the crime?

Having clocked off work the night before his holiday, DI Ross finds an abandoned baby gurgling on a doorstep on his walk home. After ringing the doorbell but getting no response, Ross checks round the back only to discover a French window wide open and a dead man lying in a pool of blood. Are the baby and the victim connected? Ross calls in the team to help with the investigation.

When a new novel includes the detailed description of a murder the same of that which belongs to an unsolved case, the team start to think the story's writer could of been involved in the murder. Burke tries unsuccessfully to find evidence to link the author to the crime but remains determined to bring him down.