Delta Rising

Star Trek Online: Delta Rising is the second expansion pack to the Star Trek Online. It was released on 14 October 2014.

Story
Delta Rising's story leads off directly from the "" episode where the Romulan Republic, Federation, and Klingon Empire collaborated in the discovery and exploration of a Dyson sphere in the Delta Quadrant, and came into conflict with other parties seeking to use the sphere: first the Voth, then the Undine. The episode's final mission, "Surface Tension" saw Earth and Qo'noS come under direct attack by the latter, leading to an armistice that officially ended the Federation-Klingon War of 2405-2410.

In Delta Rising the player begins to investigate the Delta Quadrant for the first time since Star Trek: Voyager over thirty years earlier, with the three powers, now calling themselves the Alpha Quadrant Alliance, dispatching a multinational military expedition from the Jenolan Dyson sphere into the Nekrit Expanse region. They soon come into conflict with a renewed Vaadwaur Supremacy and must forge an alliance of local races to defeat them.

Mechanics
Delta Rising added another tier to the Reputation system and raised the level cap from 50 to 60. It also added Tier 6 starships and featured the debut of additional bridge officer specializations, beginning with Intelligence officers.

Voice cast
Delta Rising featured guest appearances by five members of Star Trek: Voyager's main cast, who reprised their old roles for the expansion.
 * Tim Russ plays Tuvok, now a rear admiral and commanding officer of USS Voyager, in a recurring role in the storyline.
 * Ethan Phillips reprises the role of Neelix in "".
 * In the Kobali arc, Garrett Wang returns as Harry Kim, now a captain and CO of the USS Rhode Island.
 * Jeri Ryan returns as Seven of Nine in "" and later appears in the "Borg Disconnected" team PVE mission assisting the Borg Cooperative.
 * Robert Picardo returns as the Doctor.

In addition, Denise Crosby returned as the former Empress Sela in the featured episode "What's Left Behind", released one month after launch.