what a nice surprise this movie be . director john gilling surely know how to make a well build up thriller with a slow pace but never a dull moment . the movie be extremely well write and have some at time incredibly good dialog . the fact that this movie be base on the true story of burke and hare and two murderer who sell their victim to professor knox and who use them for his research and make the movie even more interesting to watch . this movie be not really an horror movie and i would prefer to describe it a a dark thriller . the movie doesn not have any scare but it have some well build up tension and a great thriller story . i think it be more because of the fact that cushing and pleasance be in this and that people consider this a horror movie . but please and when watch this movie and do not expect a movie with walk death people or cushing in a role of a frankenstein like professor . the movie be shoot in atmospheric black and white . it be wonderful to see both cushing and pleasance in black and white for a change . my only complaint about the style be that it be a bit too dark at time and which make the movie sometimes hard to follow . peter cushing be most certainly good in his role a dr. robert knox but it really be donald pleasence who uplift the movie with his performance . this might very well be the best performance of him i have ever see in a movie . he play a slimy tramp who be the lead murderer of the movie . his character be portray so powerful and believable without ever go over the top . it really be the way the movie be build up and the wonderful directing by john gilling that make this movie an absolutely great thriller that deserve to be good know . positive .