When self-made property developer, Niall, is attacked by vampires on his way home, his neat and ordered life soon begins to fall apart. His rescuer, the effervescent Mel, declares herself to be his Muse - better known in modern times as a Guardian Angel - and offers him a business proposition; she wants them to go into business as supernatural detectives. Slightly sceptical to say the least, Niall eventually agrees to work one case with her - helped in no small part by his rather strong attraction to Mel. Mrs Hart's house has been plagued by a series of deadly and inexplicable events, culminating in the death of a local boy. As they look into possible causes, Niall finds himself growing even more fond of Mel, although she seems determined to keep him at arm's length. He discovers why she she is so reticent but that is soon overshadowed by the cause of Mrs Hart's problems; a foe so powerful that even the immortal Mel seems terrified