Vector is the third episode of the first season, and the third episode overall. It was released on February 4, 2005.
A deadly virus is spreading through LA and only Charlie's equations can determine how far and where the disease is headed. The CDC is also on the case, and Don has to contend with a potential turf war among the authorities.
In everyday usage, the term "angle" is often substituted, however, technically, a vector is "a quantity possessing both magnitude and direction". Such distinctions lead us into Charlie's territory.
Rainn Wilson's character (Martin Grolsch) is named after one of the most popular Dutch beers: Grolsch. Grolsch is named after a town, and it's not at all a common last name, not even in The Netherlands.
When the public health officer, Lt. Havercamp, is first introduced she is introduced as "Commander." As shown by the credits and her shoulder boards (two full-size stripes), she is a lieutenant. PHS ranks are the same as navy officer ranks.
[This appears on the beginning of the episode] 4 Countries 6 Deaths 30 Cases 1 Unknown Pathogen