Joint EVE and Legion Missions.A security agent (in EVE) have a mission to retrieve some stolen documents from a rouge operative, which is hiding on his base located in somewhere in dead space. The base is heavily fortified both with ships outside and security drones on the inside.
The mission is initially accepted by the EVE player, which selects if the merc "squad" should be locked (playing with friends) or open to everyone. He then continues to load a mobile CRU into his cargo-hold, which makes the mission available in Legion. Accepting the mission (in Legion) will load you into the ships loadingbay (similar to the warbarge, but smaller). A custom channel is created where the mercs (and EVE player) can interact during the travel to the destination (they can also spawn in during the travel).
When the EVE player reaches the jump gate he needs to decide if he have enough mercs (CRU contains 50 clones total), since when he jumps to dead space the mission will be locked in Legion.
After jumping the EVE player will be engaged by the enemy, and his first objective is to eject the CRU within X km from the base (it will refuse to eject beyond that point). After ejecting, the CRU will "dock" with the station which will initiate the fight for the mercs. The mission should state which objectives needs to be met, but preferably the fight should be in tandem. I.e. to speed up the progress in the base, the EVE player can destroy objectives in space (i.e a power relay or similar), and the mercs can disable auto turrets targeting the ship by hacking the consoles in the station etc. None of these things should be required to complete the mission, but it will promote cross play for mutual benefit. If the EVE player is destroyed or the clones run out, their individual mission will fail. (both EVE player and Mercs have individual goals along with a common goal)
When the mercs have obtained the documents, they will extract the same way they came and "eject" the CRU into space again where it can be picked up by the EVE player, and returned to base.
The example mission above would promote cross play between EVE and Legion, but not make the two games fully dependent on each other, since there is nothing that forces anybody to accept the missions. The results though will be very similar to the EVE Forever video shown during Fanfest.