Since none of us worked here last year when the agreement was made with the supplier, we'll have to see if Tanaka-san can shed some light on the situation.
Light a fire under
Motivate, to cause someone to act
Yamazaki-san is going to
† have to light a fire under the architect if he wants to present the blueprints at the meeting.
See the light at the end of the tunnel
Realize that the end of a project is near
Hori-san said he can finally see the light at the end of the tunnel after five years of his research project.
In the dark
Unaware, uninformed
Miyagi-san was in the dark about the revisions to the budget for the next fiscal year.
Dark horse
An unknown candidate or contestant who has a chance to win
Doi-san was the dark horse in the race for mayor but won with 52% of the vote.