Circus Train Conspiracy

Following a string of successful performances, the Moscardi Circus is travelling by train to Newcastle for their next show. Yet a collision on the track with a couple of sleepers causes pandemonium: passengers thrown about and animals escaping into the night. When the body of a woman is discovered in nearby woodland, Inspector Colbeck is desperate to lend assistance, believing the two incidents might be connected. Who is the nameless woman and who is targeting the Moscardi's Magnificent Circus?