Emily Blunt as optimistic Scientist  Lily Houghton, searching for a tree with a magic cure

Paul Giamatti is Nilo, The dubious  harbourmaster where Frank parks  his boat

Every film needs a villain! Edgar Ramirez  is Aguirre, a deadly mercenary leading a rival expedition

Jesse Plemons is Prince Joachim, an  ambitious but deranged German  aristocrat who finances the rival  military expedition