At some point, Locke contracted cancer, which left him in critical condition. Although under treatment from Doctor Shockra, Locke's prognosis was bad, as he was unlikely to live long enough to see Ascension Day. After awakening from surgery, Locke confessed his feelings to Lara-Le and explained to Knuckles the guilt he felt over how he raised him. After this, Locke passed away overnight on the sixty-first day of 3246. (StH: #143)
In 3261 when Knuckles visited his father's grave, he revealed he learned that if he prevented his daughter from becoming a Guardian, he would be making the same mistake Locke made with him by not giving her the chance to choose for herself. He then decided he'd let her become a Guardian, at which point the spirit of Locke looked on smiling with Aurora at his side. (StH: #143)
- Due to the changes in the timeline, it is unknown if Locke is dead or not.