Doctor Arne Magnusson is a fictional character from the video gamesHalf-Life and Half-Life 2: Episode Two, voiced by actor John Aylward. He is one of the few survivors of the incident that took place in the Black Mesa Research Facility. He is found at the missile silo base in White Forest helping Dr. Isaac Kleiner and Dr. Eli Vance develop experimental technology and weapons for use against the Combine, with the intention of aiding the human resistance in their struggle. Magnusson seems to be in charge of the White Forest Rocket Facility in Episode Two but whether his position is democratically secured or self-appointed is not known. He works on his satellite delivery rocket throughout the game and has clearly been excited about the day he could finally launch it. Magnusson appears as much more of a rude and impatient character than most of those in the Half-Life game series, and Eli Vance mentions that Magnusson and Kleiner were argumentative, bitter rivals at Black Mesa, when they competed for grant money, long before the Incident. Their rivalry may also be due to personality conflict, as Kleiner's demeanor is almost diametrically opposite to Magnusson's (cf. Latin "Magnus" - large, Dutch/German "Klein" - small).
In Half-Life 2: Episode Two, Magnusson mentions forgiving Gordon Freeman for a debacle involving a "microwave casserole". This is confirmed (by the developer commentary) to be a reference to an incident early in Half-Life, where the player can accelerate the speed of a microwave, causing the food inside to explode and a nearby scientist to exclaim, "My God, what are you doing?!". According to the developers' commentary, the idea for Magnusson's demeanour came from one scientist in Half-Life who said "Gordon doesn't need to hear all this, he's a highly trained professional," as the Test Chamber doors were opened.
Magnusson appears throughout the game at the White Forest missile silo base (though often the player can only communicate with him through video uplinks), working on his rocket to deliver a payload that will close the growing Combine superportal. As stated by Alyx, Magnusson was "hoping for the day when he could launch a satellite to tap into the old array they set up at Black Mesa, but getting a launch off when the Citadel was intact... There was just no way."
Magnusson lends his name to the Magnusson Device, a special adhesive anti-Strider explosive. The weapon comes into prominent use during one critical part of the Episode, where they are given to the player as the fastest means to stop a sizable Strider attack wave. They excel at this task, since a single successful detonation causes a Strider to dramatically blast apart; in comparison, Striders can sustain multiple hits from most other weapons, and even then they usually just collapse in a heap. Valve referred to this device as the "Strider Buster" prior to the game's release.
Magnusson's peculiar personality seems to have gained him much respect from the Vortigaunts, and even to have influence on them. His assistant, called "Uriah" after Charles Dickens's character 'Uriah Heep' because of his "bowed posture and semi-servile manner", is the only Vortigaunt seen to wear clothes (a lab coat with an indentification badge). Uriah makes awed references to Magnusson such as "I can return to my place of honor, at the side of the Magnusson" and "It is an honor to have been accepted by the Magnusson". Another Vortigaunt earlier in the game also utters a phrase very similar to Magnusson's "What next in the parade of constant interruptions?" ("What next in the parade of constant obstacles?") ; the game's commentary confirms that this is intentional and that his mannerisms have spread among the Vortigaunts via their telepathic link.
