(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")
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")
Ryan is absent from the script for "The Xindi", as his act of sniping the foreman on the trellium mining planet was originally written for Major Hayes to do.
Taking its cue from the script of "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.