In 1931, along with Francis Beresford-Hope and Marwell O'Brien, Henrik Mellberg recovered an artifact related to the Tomb of the Gods in a diamond mine at the Popigai Crater, north of Norilsk, Siberia. The three made an expedition of fifteen men to follow the map on the key, and reached the Tomb of the Gods. Only Marwell, Beresford-Hope, and O'Brien survived the expedition, and according to Beresford-Hope's son, Alex, all three men had lost their sanity. Realizing the secrets they had found, the three discoverers split the key into three and each kept a piece.