When You're Lost in the Darkness

Lore & Background

The episode opens on a 1968 talk show where two epidemiologists debate whether a fungus could ever infect people; one warns that a warming world could let fungi adapt to body heat. In Austin, Texas, in 2003, fourteen-year-old Sarah wakes to find the outbreak of a mutated Cordyceps fungus under way, and she, her father Joel and his brother Tommy try to flee the city. Twenty years later, Joel and Tess set out to find Tommy and take on a job smuggling a young girl, Ellie, in exchange for supplies.

Johan Renck was first set to direct but left over scheduling problems caused by the COVID-19 pandemic, and his replacement Kantemir Balagov left over creative differences, so Mazin directed it himself. The script began as two episodes, merged because HBO felt the original first hour would not bring viewers back. Filming on the series started in Calgary, Alberta, in July 2021. The premiere drew 4.7 million viewers on its first day and almost 40 million within two months, and won Emmys for sound mixing and sound editing.

Did You Know?

• The premiere was originally written as two separate episodes.
• Mazin took over as director after two other directors left.