Ballard asks Adelle regarding Echo, "So if she floats, she's a witch." This is in reference to the popular belief that the 17th century practice of dunking in witch trials would only prove a woman innocent if she drowned.
Patton Oswalt reprises his role of Joel Mynor; the Internet Mogul whose wife passed away years ago. Sadly, such became true of Patton Oswalt's wife in real life who passed away in April of 2016.