Add a rule titled “Companions have locations” with the following body.

The Companion (if any) of each Traveller has a Companion’s Temporal Location (CTL), which is tracked in the GNDT as a Game Date in Standard Form.  At the point of creation, new Companions start at the TL of the Traveller of whom they are a Companion.

Add a rule titled “Travellers leaving Companions”.

If a Traveller and eir Companion are at the same location, then when the Traveller’s TL changes, at the same time, the CTL changes to the same value.  However, when a Traveller changes eir own TL, e may choose not to change the CTL if e wishes.

For each Traveller that has a Companion, set eir CTL to eir TL.