In X-tale they have started working on a train line that would run through all the AU's, so they had been working for more than 6 months. The route began in Undertale, and the final destination was X-tale. By coincidence, Cross and INK were spending a few days in undertale, and they were already due to return to X-tale, Cross's AU.

".........."

Cross and INK decided to go to the "Underverse Express" train station, which was just outside of Undertale's Snowdin. Once the Train arrived, they both got on and Cross fell asleep hugging INK while the trip went by. The entire trip to X-tale was 5 days, and the train was rustic and old. so there was no rush or danger, for now:

".........."