Left to their own devices, Clara decides to send a message to earth and ask the human race what to do, telling them to turn off their lights if they want to kill the creature, but leave them on if they want to let it be. This gives us a good shot of the lights on the earth below which shows the outline of the exact same coastline as today. Odd that the coast hasn't moved at all, considering we've been told that high tides (due to the increase in the moon's mass) are destroying the planet. Oh well, it's not like you expect any better out of the episode at this point.
Clara, Courtney, and Lundvik run down a corridor that explodes behind them for no apparent reason and then watch as lights go out across the globe, sending the overwhelming message that humans are jerks who would rather kill an alien and probably kill themselves than risk an unknown danger -- which certainly proves the Doctor's assumption that humans are stupid and dangerous. With the entire globe dark, Lundvik presses the button to activate the bomb... but Clara gets in her way and presses the abort button.
It's now that the Doctor shows up to whisk them all away to safety -- he'd had a good idea all along of what would happen -- landing on a beach so they can watch the egg hatch. The eggshell dissipates, causing no risk to the planet, and the alien lays a new egg that looks just like the moon before it flies off into space. How convenient!
The episode's most interesting moment comes at the end, when Clara takes the Doctor to task for manipulating the situation and abandoning everyone. He definitely deserves it, but since he doesn't seem to understand why Clara's upset it seems unlikely that he'll change his ways. However, Clara tells him she's done with him -- telling him to go away before she leaves the TARDIS. It's a great emotional moment for Clara... and it will be interesting to see how the Doctor responds to it in future episodes.
Still, it's a little exhausting to continue to watch the Doctor being the universe's biggest jerk to everyone he encounters. While a gruff attitude gives Capaldi a nice contrast to Smith and Tennant, it's getting less and less fun to watch him traveling the universe just to insult everyone he meets. Next week we'll see him without Clara, though that seems unlikely to make him any warmer than he is now. Still, I'll be tuning in to find out.
Bottom Line: This episode is a string of scenes that don't make a lot of sense, but are vaguely held together by virtue of the fact that they all happen on the same channel in the same one-hour period. The last scene, however, is genuinely good.
Recommendation: Unless you're a serious fan who wants to see it all for continuity purposes, I can't recommend watching anything more than the last 5 minutes.