Unbelievable. Horrible. James Doohan, who played Capt. Montgomery Scott on Star Trek from 1966 to 1969, and again in seven Star Trek films and the Next Generation episode "Relics," died this morning at age 85. Doohan disappeared from public life last August, when he revealed that he had Alzheimer's Disease.

His character, Montgomery Scott -- affectionately called "Scotty" by his crewmates, was the archetype of Starfleet engineers. In every episode, he managed to keep the ship together despite seemingly insurmountable difficulties. He later confided in Enterprise-D chief engineer Geordi la Forge that the secret of his success was to tell the captain it would take double the time it would actually take to perform repairs. That way, when repairs were complete in half the time Scott said they would be done, the captain was impressed.

Doohan was Canadian, even though his character was Scottish. Like Walter Koenig, who played Pavel Chekov with a Russian accent, Doohan played Scotty with a Scottish accent.

Doohan is survived by the rest of the Star Trek cast, except for DeForest Kelly, who played Dr. Leonard H. "Bones" McCoy. He died in 1999.