 It was the first crossover between the two publications; three more have since followed.It was also a crossover with another "2000 AD" series, "Strontium Dog", as it featured the second occasion on which Judge Dredd confronted Johnny Alpha (the lead character in "Strontium Dog").It was written by Garth Ennis (based on an idea by John Wagner) and illustrated by Carlos Ezquerra, Peter Doherty, Dean Ormston and Chris Halls.