Complex sentence: Alex goes to Trier to use a teleportation gate to reach JC's hiding place in Antarctica--while in Trier, Alex meets up with Tong and is sent to save key figures from being killed by the Templars, learning of the Illuminati's involvement.
Split into simpler sentences: Alex goes to Trier to use a teleportation gate to reach JC's hiding place in Antarctica. While in Trier, Alex meets up with Tong and is sent to save key figures from being killed by the Templars, learning of the Illuminati's involvement.