Mike, Lucas, and Dustin discuss Vale of Shadows, a dimension alternately referred to as the upside-down, and the threshold of which Chief Hopper appears to have just discovered. Flecks of netherworld dust surround him, as they did Barb at the bottom of the empty swimming pool.
The boys probe their science teacher for more information about the upside-down, and later Dustin has an epiphany about an offsetting magnetic field. He convinces his friends that it will lead to Will. They set out to find the upside-down entryway, with a very troubled Eleven in tow.
Lucas becomes frustrated when nothing seems to come of the search. He turns on everyone, fed up with Eleven's strange behavior. In an effort to defend Mike, Eleven sends Lucas flying backward--another healthy nod to Stephen King heroines.
The fruitless search for the entryway is paralleled by flashbacks of Hawkins lab. These experimental segments with Dr. Brenner are particularly disturbing. Eleven is lowered into an underwater portal, providing her with access to the wet darkness of another dimension.
The upside-down is more within reach than everyone realizes. Another portal will be found, and the threat of the monster will again be at hand, hence the succeeding episode, "The Monster." But nothing is predictable here.
The four young leads continue to deliver performances which border on the magnificent, and Matthew Modine is delightfully cold and scary. Pop references and reverberated beats abound, as do genuine thrills.
Awesome storytelling.