ἐπὶ ξυροῦ γὰρ ἀκμῆς ἔχεται ἡμῖν τὰ πρήγματα → our affairs are balanced on a razor's edge, our affairs are set upon the razor's edge
time just before dawn: P. and V. ὄρθρος, ὁ, P. τό περίορθρον.
darkness: Ar. and V. κνέφας, τό (also Xen.).