Lockdown is the 8th mission in the GDI campaign. During this mission, Parker and his loyal forces successfully escaped the GDI Supermax Facility to rendezvous with Colonel James and continue their war against Kane.
Following James' insurgency against the GDI government and her attack on New Adana, General Riggs had her and the crew of the GST Tzadik arrested. The crew and Parker were detained at the Supermax facility in the Arctic Circle awaiting their sentence. James however had somehow managed to escape from the prison but her war against Kane could not continue without Parker's support. While Parker was imprisoned, he learned of the brutal murder of Doctor Pascal by Nod Separatist leader Gideon and that he was the last of the five recipients of the optical implants that Parker had.
A short time later a mysterious agent known as Duquette released Parker from his cell and organized a 10-minute gap in the facility's security patrols to escape.
By the time Parker escaped and re-assumed command of GDI rebel forces, the Supermax prison had learned of his escape and put their defensive forces on high alert. Duquette initially managed to supply Parker with two drop pods worth of loyal Zone Enforcers and engineers, but Parker was forced to capture a nearby uplink tower before he could call in reinforcements. Now having access to Crawlers, Duquette informed Parker that the tractor beams holding the GST in place could be disabled by Engineers through four different generators throughout the facility. With the ironic support of some of Gideon's rioters, Parker's forces fought back the prison's security forces and disabled the tractor beam, allowing the Tzadik to escape the area.
As the media started to speculate on how the coup leaders managed to escape, Col. James remained as focused as ever on her campaign against Kane. Learning of a rally that Kane was holding near Threshold-19, James planned to infiltrate the rally and kill Kane with a sniper rifle.