A charity hospital in 1893 San Francisco where the Devidians, posing as a doctor and nurse, drain the life energy of cholera patients until Picard's team intervenes.
The Sisters of Hope Infirmary is a hospital for the poor in San Francisco, seen in the Next Generation episode Time's Arrow, Part II. A cholera outbreak has filled its wards, giving the Devidians an ideal cover: deaths among such patients attract no attention, so the aliens can feed on human neural energy unnoticed.
Picard's away team, having followed the Devidians to 1893, investigates the suspicious deaths. Beverly Crusher works in the infirmary as a nurse, while Riker passes as a policeman, and they identify a visiting doctor and his nurse as the disguised aliens.
When the team confronts the pair and seizes their snake-headed cane, which controls the time portal, a struggle breaks out and the real police arrive. The officers have to flee the building, pursued by an increasingly suspicious Samuel Clemens.