The surviving colonists build a light tower to try to signal the Resolute.
Maureen, noticing strange weather phenomena, conducts an experiment using a weather balloon. She discovers the sun is paired with a deadly black hole, and that the disturbances will only get worse until the planet gets entirely unhabitable.
A decent episode that slowly moves multiple plots along.
That is, until a confrontation with a CGI creature and the robot turns up in the nick of time for a neat CGI battle. Dr Smith beginning to look like an ineffective villain, wandering around and poking into everyone’s business.