Expresses a tentative possibility, often with a sense of slight doubt or speculation. Common in both spoken and written Japanese.
ひょっとすると、彼はもう来ないかもしれない。
Perhaps he won't come anymore.
ひょっとすると、明日は雨が降るかもしれない。
Maybe it will rain tomorrow.
Perhaps he might not come.
Maybe he already knows the answer, doesn't he?