A number of stories have to take place during FF@ 21, because the FF return from the events of FF 317 (the end of a long-ish story) at the start of FF@ 21, and then Crystal leaves the team by the end of FF@ 21. The only spot for a break is after the FF shower and before the Inhumans contact them, so between pages 6-7.
CRYSTAL/CRYSTAL AMAQUELIN [INHUMAN]
…
FF 317
*FF@ 21 (1-6)
FF 342-FB
*FF@ 21 (7-30)
FF@ 21/2
…
HUMAN TORCH II/JOHNNY STORM
…
FF 317
*FF@ 21 (1-6)
FF 342-FB
M/CP 67/3
M/CP 68/3
*FF@ 21 (7-30)
FF 318
…
MS. MARVEL II/SHARON VENTURA
…
FF 317
*FF@ 21 (1-6)
FF 342-FB
*FF@ 21 (7-30)
FF 318
…
THING II/BENJAMIN J. GRIMM
…
FF 317
*FF@ 21 (1-6)
FF 342-FB
M/CP 3/4
ST2 19
M/CP 66/3
M/CP 67/3
M/CP 68/3
*FF@ 21 (7-30)
FF 318
…