(covers information from several alternate timelines)
In September of 2153, Ryan accompanied Lieutenant Malcolm Reed and Major Hayes on a mission to the trellium mining planet to rescue Captain Jonathan Archer, Commander Tucker, and Kessick. Following a directive from Hayes, Ryan sniped the foreman of the planet's north mine, using the targeting scope on his particle rifle. (ENT: "The Xindi")
Later that month, he assisted in an unsuccessful effort to stop a group of Osaarians from boarding and looting Enterprise. He threw a stun grenade when discovering the pirates inside armory but the Osaarians beamed aboard. (ENT: "Anomaly")
Ryan was part of S. Money's MACO team which took position near one of the airlocks when a Xindi-Reptilian warship docked and a Xindi-Reptilian boarding party blew off the hatch. Ryan and the other MACO opened fire but had to withdraw. When Money was hit by an energy discharge, Ryan helped her get around the next corner. (ENT: "Rajiin")
In November 2153, Ryan was confined to some quarters by a group of Triannon who took over Enterprise. Later, he assisted Captain Archer retake the ship and fired at some Triannon in engineering. (ENT: "Chosen Realm")
Ryan and Corporal Chang guarded the entrance to a crash landed Xindi-Insectoid starship on which Captain Archer tried to hatch the vessel's youth. Both MACOs denied T'Pol access to the Xindi-Insectoid hatching chamber. (ENT: "Hatchery")
Ryan was also among numerous crew members who, in Enterprise's launch bay, listened to Captain Archer deliver a speech in remembrance of all the crew members who had lost their life in the Delphic Expanse. (ENT: "The Forgotten")
On February 13, 2154, Lieutenant Malcolm Reed asked the MACOs for volunteers to join the mission to board the Xindi weapon. All the MACOs volunteered, including Ryan. Though Reed chose Romero, M. Forbes, and W. Woods for this assignment, Ryan later defended Enterprise from a boarding group of Sphere-Builders. (ENT: "Countdown", "Zero Hour")
The same year, Ryan and W. Woods arrested Lieutenant Malcolm Reed because of treason. They brought him into the ship's brig while Enterprise's crew also had to deal with Klingon Augments. (ENT: "Divergence")
Corporal Ryan and Private Woods accompanied Captain Archer and Lieutenant Reed on board Harrad-Sar's barge, where Harrad-Sar offered them drinks and food. Like every other male present, Ryan was hypnotized by the performance of three Orion slave girls – D'Nesh, Maras, and Navaar. (ENT: "Bound")
Background information Edit
Ryan was initially absent from the final draft script of "The Xindi", as his act of sniping the foreman on the trellium mining planet was originally written, as of 17 June 2003, for Major Hayes to do. As of 10 September of that year, however, the character in this scene was simply referred to as "a sharpshooter", in the episode's final draft script.
Taking its cue from an early draft of the script for "The Xindi", that episode's novelization (included in the book The Expanse, together with the novelization of ENT: "The Expanse") does not feature Ryan either, with Hayes instead assuming his act of shooting the foreman.