 PLOT: After being electrocuted and hit over the head with a crowbar,  Sebastian is still very much alive and in good shape, considering.  No mention is ever made that the invisibility serum also provides  the subject with invulnerability and superhuman strength. A normal  man would be killed if he were hit over the head with a crowbar.  Also, lying on top of uninsulated steam pipes would have burned  Caine, as would the escaping steam.