Literary villain, one requesting a lift across northern suspension bridge, heading for trouble (7,7)

'literary villain' is the definition.
(villain in Lolita)

'northern suspension bridge heading for trouble' is the wordplay.
'northern suspension' becomes 'humbert' (I can't justify this - if you can you should give a lot more credence to this answer).
'bridge' becomes 'humber' (Humber Bridge is an example).
'heading for' suggests taking the first letters.
The initial letter of 'trouble' is 't'.
'humbert'+'humber'+'t'='HUMBERT HUMBERT'

'one requesting a lift across' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.