Buried beneath four kilometers of solid Antarctic ice lies a body of liquid water the size of a sea, sealed off from sun, wind, and atmosphere for 15 to 25 million years. It is the ultimate locked-room mystery, and we may have already contaminated it.

This episode dives into the physics, discovery, and controversy of Lake Vostok, pulling from geological records and a vast catalog of scientific research. We explore how liquid water survives in the coldest place on Earth, why astrobiologists are obsessed with it, and the decade-long fight over how to drill in without destroying it.

• How 345 bars of pressure lower the melting point and keep the lake liquid at minus 3 degrees Celsius
• The decades-long puzzle of Russian seismic soundings, British radar flatlines, and 1993 satellite lasers that confirmed the lake
• Why the  ...