The episode begins around a familiar fire, with Sizer pacing it, explaining that the Council of the Elements gave him a lead on a shard in Rubik as well as new orders. The orders were to get the red, black, and blue shards and insert them into the walls at the Makyne as a defense against intruders. He then goes on to suggest searching the Makyne first, for any shards unfound or left behind. This speech of his quickly turns into the one from the beginning of The Shard Part 1: Up, Up The Mountain, and I look super clever because of it.
The story then shifts to the Party of Crystal, once again in present times, at the Makyne, as they insert the shards into the walls as per their directive. And, as you probably know, the ruins begin to fall apart, and all that stuff from the Prologue happens, with the giant hand coming down and the whole ruins rising up.
And then it ends. Cliffhanger for season two!