Go down and look over the southeast (4)
I believe the answer is:
lose
'go down' is the definition.
(I've seen this before)
'look over the southeast' is the wordplay.
'look' becomes 'lo' (archaic exclamation meaning 'look!').
'over' means one lot of letters go next to another (in a down clue, some letters go over others).
'the southeast' becomes 'SE' (synonyms).
'lo'+'se'='LOSE'
'and' is the link.
(Other definitions for lose that I've seen before include "Mislay - fail" , "Don't win" , "Cease to have" , "Fail to win" , "Mislay or be defeated" .)