The SQuare is a tablet computer, used to give Dak, Sera, and Riq information by the Hystorians. It gives the trio info on the Great Break and where to find the local Hystorian. In Curse of the Ancients, Sera removes some brackets in an attempt to make a lock pick, knowing that the SQuare would continue to function. In Behind Enemy Lines, the SQuare is destroyed, so Dak and Sera go to the future (but not Riq, as he deleted his ancestry) to get a new SQuare with info on the Prime Break. In the Smyth's lab, a woman hands them the SQuare. It is revealed, she is Tilda. Sera uses the Infinity Ring to return to World War II, bringing Tilda with them.