① If a monster(s) is Summoned: Destroy all monsters on the field.
● Like most Trap cards, this card can miss the timing.
For example, if "Jar of Greed" was activated,
and "Call of the Haunted" is chained to it,
this card cannot be activated when that monster was Summoned,
as the Summon was not the last thing to happen
(Jar of Greed drawing a card was).
You can read more about Timing here: