Dr. Isaac Kleiner is a Caucasian American scientist. An archetypal 'absent-minded genius scientist' (although somewhat more benign), 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) leaders of the Earth Freedom Fighters against the Axis, and a prime member of the Resistance science team, After the death of Eli Vance, Kleiner takes place as the main leader of the EFF, and later on the first President of the Human-Vortigaunt Federation post-Golmar Civil War. His most notable work would be the works he and Drs Eli Vance and Gordon Freeman made that became instrumental to the creation of the Kleiner-Freeman-Vance Drive Systems, the primary non-Combine, and non-Ancient method the wider Multiverse uses for multiversal travel.
