The same two letters, in the same, consecutive order, will change each word below into a new one.

BE
DIG
GAS
FINE
POLE
BAND
STING

Answers:

The letters are IT:

BITE
DIGIT
GAITS
FINITE
POLITE
BANDIT
SITTING

Credit: LA Times Crossword
September 25, 2011
Jeffrey Lease
IT'S A SURPRISE