PDQ
abruptly
all at once
all together
apace
at a blow
at a stroke
at once
at one blow
at one jump
at one stroke
at one swoop
at one time
away
decisively
directly
expeditiously
immediately
in a hurry
in no time
instanter
instantly
now
on the instant
on the spot
per saltum
pretty damned quick
promptly
pronto
quickly
right away
right now
right off
simultaneously
smartly
speedily
straightaway
straightway
subito
sudden
suddenly
summarily
swiftly
then and there
this minute
this very minute
uno saltu
Blyth
Fifth
Smith
Smyth
fifth
frith
herewith
myth
pith
scythe
smith
stith
with
withe
writhe