"He fled from the convoy to this wilderness." Viktor answers, detailed and objective. Why had Jayce run off? Irrelevant. The 'why' does not matter, only the from where and to where.

When is another matter. Viktor cannot fully recall. He feels so detached from the perception of time. There is an answer, a factual one, he is unaware of it.

"How long it has been is unknown. I have been pursuing him ever since." Which implies that Jayce has not wanted to be found.