This is the second time Cassandra has generated interest from other women. She was previously cast in the role of Prince Charming by a magical storybook. Here, she literally charms the earrings off of an Italian heiress, and gets her phone number in the process.
Stone is doing a density comparison on the chess sets by immersing their bottom halves in water. This inaccurately alludes to the classic Archimedes solution for measuring the density of irregular solid shapes. By immersing the entire object in water and noting the increase in water volume you get the volume of the object. Measure the weight and you get weight/volume, which is density.
Episode title "And the Drowned Book". At the end of Shakespeare's 'The Tempest' the magician Prospero gives up magic by drowning his book of spells.
David S. Lee, who played Moriarty in Season 2, also played a character in another Dean Devlin production. In Leverage (#1.6) The Stork Job he played Nicolas Petrovic, who most notably was the guy Parker (Beth Riesgraf) stabbed with a fork.
The 'weather sonar' shows the storm spinning in a clockwise pattern. At the northern latitude of NYC over 98% of tornado force storms and all hurricanes move counter-clockwise. Maybe the show's graphics crew got it wrong or maybe the writers did this to subtly highlight the unnatural character of the storm.