Watch on Soap2day. In the last six years, the remains of over 90 people have been recovered from the canals of Greater Manchester; most are young men. Now headlines have claimed a serial killer, dubbed by locals as ‘The Pusher’, could be at large. In this documentary, ex-murder detective Tony Blockley reviews the cases of three young men who mysteriously drowned and whose parents are desperate for answers. Is it possible a serial killer is stalking Manchester’s waterways?