A teenage boy is sucked into an ancient world when he finds himself lost in the ruins of a lost civilization, and hunted by by monsters of the dark.

Agree with Richiev. ?The logline sketches a situation, but not a plot. ?And a logline should sketch a plot. ?So as a result of "being sucked" into an ancient world, what must he do about his predicament? ?What becomes his objective goal?

How did he get "sucked into" an ancient world in the 1st place? ?Please clarify "sucked into".

This is a situation... What he must do about it is the story. The logline will be improved if the lead character has a stated goal.