A player character falls into a 10-foot × 10-foot concealed pit trap, which is 20 feet deep. At the bottom of this pit is a gelatinous cube, which occupies all of the bottom 10 × 10 × 10 (width × height × depth) area of the pit.
The statblock for a gelatinous cube (from the Monster Manual, page 242) indicates that when a creature enters the cube's space (e.g. by falling into it, in this case), it's subjected to the cube's Engulf ability and has disadvantage on that saving throw.
If a character falls into the pit trap, but succeeds on the saving throw against the gelatinous cube's Engulf, what space does the character end up in?