﴿ فَإِنَّمَا هِىَ زَجْرَةٌۭ وَٰحِدَةٌۭ فَإِذَا هُمْ يَنظُرُونَ ﴾

“for that [resurrection which they deride] will be [upon them of a sudden, as if it were] but a single accusing cry - and then, lo! they will begin to see [the truth]”

For it will be only innamā hiya this hiya is a demonstrative pronoun explained by the following zajratun a single cry and lo! they all creatures will be alive watching to see what will be done with them.