Jonathan Ishii

"Huh? No! No! Please! You must let me get this communication out! They have to be warned while there is still time!"

- Jonathan Ishii, upon meeting the Marine

Dr. Jonathan Ishii was a scientist and part of the Delta Science Team. He went missing before the Marine arrived on Mars.

History
The player's first assignment in Doom 3 is to find Jonathan Ishii. Sergeant Thomas Kelly assigns the player this assignment and sends him to the old communications facility, following reports that Jonathan was spotted heading in that direction. Sergeant Kelly instructs the player to bring Jonathan back unharmed.

When the player finds Jonathan, he panics and begs the player to let him send a transmission to Earth warning them of Dr. Betruger's experiments. Jonathan cryptically adds, "The devil is real. I know, I built his cage." Suddenly, the main portal in Delta Labs activates and demonic spirits come pouring out. Jonathan is possessed by one of these demon spirits (as are the majority of personnel throughout the base) and he becomes a zombie as a result, forcing the player to kill him. Jonathan is the first enemy the player faces in the game.

Email - Code-Black: Missing Staff (11-15-2145)
This email can be downloaded directly from an information terminal in Mars City.

Note: The email cannot be downloaded after returning from the old communications facility.

''Dr. Jonathan Ishii from the Delta Science Team is missing. Security is concerned that he may be injured and unable to respond to pages or return to his post. Please keep an eye out for Dr. Ishii and report to UAC Security if he is located.''

He was last seen in Mars City Underground approaching the airlock leading to the old communications array.

Trivia

 * It is possible to kill Jonathan before he is possessed.
 * Judging from his discussion with the player, It is possible that Jonathan and many others helped to create a new portal to another dimension, namely hell. Upon knowing about Hell's existence and the horror that comes along with it, Jonathan started to go AWOL and he tried to send a communication signal to somewhere, but it failed due to the invasion.
 * According to the Making of Doom III book, the original story called for Jonathan to commit suicide by shooting himself in the head.
 * You can read the transmission Jonathan is trying to send on the screen in front of him. The message warns that if the portal backwashes, no biological entity would survive the blast radius. Trying to send the message will result in an error and short video of a zombie killing a Marine.
 * Ishii is referenced in Doom Eternal: The Ancient Gods, Part One in the Blood Swamps, there is a castle found in the level named Ishii Keep.