Counselor Troi suggests the ship celebrate Halloween while a mysterious entity begins to spread through the ship, feasting on fear. crewmen begin to go missing all over the ship. soon the entity reveals itself to be Redjac. the crew begins to feel the weight of fear and anxiety, some of them come to Troi for help. Data enters the Holodeck and encounters the missing Lt Bloch, possessed by Redjac and in the garb of Professor Moriarty. Bloc injects Borg Nanites into his body and easily decapitates Data. Data is modified by Bloc into a Frankenstein's Monster type of being.
Lt Bloch is a nod to writer Robert Bloch. who not only wrote Psycho but three episodes of TOS. Redjac comes from TOS episode 'Wolf in the Fold', also written by Bloch. this is not the first time the TNG crew have encountered Redjac. the Wildstorm one-shot 'Embrace The Wolf' has similar Holodeck scenes. in fact i do wonder if that story is cannon with this new one, as the TNG crew seem familiar with Redjac.
This is a very fun issue. the introduction of the Borg Nanites is perhaps a bit much. as Jim Cornette would say, 'Its a hat on a hat!' you have Redjac possessing Lt Bloch, who is dressed as Professor Moriarty... who is now partially assimilated. seeing Data done up like Frankenstein's Monster is pretty cool. my advice for this issue is to simply go along for the ride and have fun with it.
eight out of ten.