 There were five main storylines in the run . The first , collected as " Original Sins " , deals with John travelling to America to exorcise a demon , Mnemoth , and investigate a strange cult known as Damnation 's Army , crossing paths with a demon called Nergal ( from whom he gains demon blood ) , and having to be responsible for killing an old friend , Gary Lester , and betraying another , called Zed , in the process . The following four issues , " The Devil You Know " finally explain John 's failure to save a young girl , Astra , from a demon in Newcastle , an event that left him near insane and incarcerated in an asylum known as Ravenscar , and still haunted him to the comic 's end . He eventually discovers that the demon responsible for this was Nergal , and uses a technological scheme to trap him , and lead him back to hell . It also contains a crossover with Swamp Thing , where Constantine loses his body while the Swamp Thing uses it to procreate . 
 <a href='dey_it' title='1'><mark>There</mark></a> <a href='uninflect' title='2'><mark>were</mark></a> five main storylines in the run . The first , collected as " Original Sins " , <a href='uninflect' title='3'><mark>deals</mark></a> with John travelling to America to exorcise a demon , Mnemoth , and investigate a strange cult known as Damnation <a href='null_genetive' title='4'><mark>'s</mark></a>Army , crossing paths with a demon called Nergal ( from whom he <a href='uninflect' title='5'><mark>gains</mark></a> demon blood ) , and having to be responsible for killing an old friend , Gary Lester , and betraying another , called Zed , in the process . The following four issues , " The Devil You Know " finally explain John <a href='null_genetive' title='6'><mark>'s</mark></a>failure to save a young girl , Astra , from a demon in Newcastle , an event <a href='null_relcl' title='7'><mark>that</mark></a>left him near insane and incarcerated in an asylum known as Ravenscar , and still haunted him to the comic <a href='null_genetive' title='8'><mark>'s</mark></a>end . He eventually <a href='uninflect' title='9'><mark>discovers</mark></a> that the demon responsible for this was Nergal , and <a href='uninflect' title='10'><mark>uses</mark></a> a technological scheme to trap him , and lead him back to hell . It also <a href='uninflect' title='11'><mark>contains</mark></a> a crossover with Swamp Thing , where Constantine <a href='uninflect' title='12'><mark>loses</mark></a> his body while the Swamp Thing <a href='uninflect' title='13'><mark>uses</mark></a> it to procreate . 
It was five main storylines in da run . Tdafirst , collected as " Original Sins " , deal witt John travelling to America to exorcise a demon , Mnemoth , and investigate a strange cult known as Damnation  Army , crossing paths w/ a demon called Nergal ( from whom he gain demon blood ) , and having to be responsible for killing an old homie , Gary Lester , and betraying another , called Zed , in thdarocess . Thedallowing four issues , " The Devil yu Know " finally explain John  failure to save a young gurl , Astra , from a demon in Newcastle , an event left him near insane and incarcerated in an asylum known as Ravenscar , and still haunted em to the comic  end . He eventually discover dat the daon responsible for this was Nergal , and use a technological scheme to trap him , and lead him back to hell . It also contain a crossover with Swamp Thing , where Constantine lose his body while the Sdap Thing use it to procreate .