Dr. Isaac Kleiner is one of the main characters of
Half-Life 2 and its episodes. An archetypal '
absent-minded genius scientist', he is a prolific author of several works on teleportation and interdimensional travel, and one of the few survivors of the
incident that took place in the
Black Mesa Research Facility. Later on, he becomes a key (if somewhat self-conscious) leader of the
Resistance against the
Combine, and a prime member of the Resistance science team.
