Then > (I.e. just before midnight, since the night was divided into four watches of three hours each, starting at 6 p.m.)

7 That brazen door flew open, and in went

brazen > {Strong as brass; hardened: it is described as made of "yron" at 311.54:7 and 312.3:3}

8 Bold Britomart, as she had late forecast,

late > lately forecast > planned

9 Neither of idle shows, nor of false charms agast.

of idle shows > by empty appearances of > of; by charms > spells agast > frightened

312.30

So soone as she was entred, round about
2 She cast her eies, to see what was become
Of all those persons, which she saw without:
4 But lo, they streight were vanisht all and some,
Ne liuing wight she saw in all that roome,
6 Saue that same woefull Ladie, both whose hands
Were bounden fast, that did her ill become,
8 And her small wast girt round with yron bands,
Vnto a brasen pillour, by the which she stands.

1 So soon as she was entered, round about 2 She cast her eyes, to see what was become 3 Of all those persons whom she saw without: