In 2013, Peltz co-founded Mystery Science with Keith Schacht. Mystery Science creates open-and-go lessons for elementary teachers and helps them teach science without requiring a background in science. A couple notable interviews with Y Combinator, one their investors, detailed an unconventional business model in which the company sold to schools and districts across the United States without a sales team. Mystery Science has grown to be the most widely used science resource in American elementary schools; it is used by more than 50% of elementary schools reaching more than four million children each month. In October of 2020, Mystery Science became a wholly owned subsidiary of Discovery Education.