Star Trek Discovery: Every Easter Egg & Hidden Reference From 'That Hope Is You'

Another notable event in the history of the future (of the future) that Book tells Michael about: The Gorn destroyed subspace.

This is yet another name-check of the famous "Arena" reptiloids in modern Trek (though they did finally get a cameo in Lower Decks' "Veritas"), but this is a big one. According to Book, the Gorn destroyed a two light-year swath of subspace, the honeycomb-like realm that facilitates everything from warp travel to faster-than-light communications in the Star Trek Universe.

Later in the episode, we learn that the Federation remnant is severely limited in its ability to scan space, with long-range sensors having failed years prior. It's possible that the Gorn and other races damaged or destroyed the fabric of the Star Trek Universe by attempting to find new, more dangerous modes of FTL transit or communications after The Burn... but we'll obviously have to wait for more details as the season progresses.