From The TV IV

Season One of Stargate Atlantis premiered on July 16, 2004. This season saw the arrival at Atlantis and the subsequent introduction of the Wraith, a deadly enemy that was capable of beating back the superior technology and firepower of the Ancients by sheer numbers. Season One also features the ZPM search plot thread, with the Atlantis team attempting to find an Ancient Zero Point Module to power up the Lost City's defenses, a search that intensifies in later episodes as the Wraith send a massive attack force with the intention of capturing the Lost City's intergalactic-transit capable Stargate and finding a way to use it to invade our galaxy, which they consider to be a massive, unspoiled food source.

[edit] Episodes

#	#	Title	Airdate
1	1	Rising (1)	July 16, 2004
2	2	Rising (2)	July 16, 2004
3	3	Hide and Seek	July 23, 2004
4	4	38 Minutes	July 30, 2004
5	5	Suspicion	August 6, 2004
6	6	Childhood's End	August 13, 2004
7	7	Poisoning the Well	August 20, 2004
8	8	Underground	August 27, 2004
9	9	Home	September 10, 2004
10	10	The Storm	September 17, 2004
11	11	The Eye	January 21, 2005
12	12	The Defiant One	January 28, 2005
13	13	Hot Zone	February 4, 2005
14	14	Sanctuary	February 11, 2005
15	15	Before I Sleep	February 18, 2005
16	16	The Brotherhood	February 25, 2005
17	17	Letters from Pegasus	March 4, 2005
18	18	The Gift	March 11, 2005
19	19	The Siege (1)	March 18, 2005
20	20	The Siege (2)	March 25, 2005