It continues to travel through space towards us but the space expands to fast for it to "catch up". Unless something is tightly enough connected to counteract this, it will happen to everything separated by space. The current models even predict that in the far future, the only information available will be that from the local cluster of galaxies. The space between our cluster and the other ones will, although it is relatively small today compared to the visible universe, expand at a faster and faster rate. 1 unit of space becomes 2 units of space in some time, then 4 units of space, 8 etc...

We are actually fortunate that we may observe light all the way back to where it started! The "observable horizon" is still behind the beginning of time, so to speak.