Number One (Babylon 5)

Number One/Theresa Holloran
Babylon 5 character
Tessa Holloran, aka Number One
First appearance	Racing Mars
Last appearance	Objects at Rest
Portrayed by	Marjorie Monaghan
Information
Species	Human
Home planet	Mars
Affiliated with	Mars Resistance, Interstellar Alliance

Tessa Holloran, also known as Number One, is a recurring fictional character in the television series Babylon 5, and was portrayed by United States actress Marjorie Monaghan. On the show, Number One was initially the leader of the resistance movement on Mars and later became head of covert intelligence for the Interstellar Alliance. During the time frame Babylon 5 takes place, Mars was a human space colony seeking (at times violently) independence from the Earth Alliance, and the issues on the red planet were story elements throughout the Babylon 5 series.

Number One first appeared in the series during the season 4 episode "Racing Mars", when Dr. Stephen Franklin and Marcus Cole travel to Mars to meet with the resistance leaders there. The names Number One, Number Two, etc. were used on Mars by the resistance to protect the identity of its leaders. Once there, Franklin manages to convince her to stop her fellow members from attacking civilian targets, citing that such acts only weaken their position, and to support Capt. Sheridan's Earth Alliance Civil War efforts against President Clark.

Later in the show, she provides assistance to Dr. Franklin, Michael Garibaldi and Lyta Alexander as they form a plan to break Sheridan free from prison, events depicted in the episode "Between the Darkness and the Light". During the time that Franklin is on Mars, he and Number One develop a friendship that turns into something more, and the two would rekindle that relationship later in the series.