an annoy group of ex student from monte alto international high school decide to spend a night in the now abandon institution where a amystery killer call the watchman play by horror legend paul naschy murder them off one by one . school killer feature some reference to such teen slasher staple like scream or friday the 13th . the climatic twist end look like lilt from the sixth sense . the uncertainty about whether the homicidal watchman be alive or dead provide some mild interest and but the character be one dimensional and the endless scene of walk through dark school corridor really get on my nerve . the presence of charismatic paul naschy almost save this clichéd slasher flick . there be also some decent gore on display include a splendidly bloody beheading . it nice to see manuela velasco of rec fame in a small role . 4 out of 10 .