The Summer's Freedom Dwindling

From "The Ministry of Fear," North (1975):

On long vacations, then, I came to life
In the kissing seat of an Austin Sixteen
Parked at a gable, the engine running,
My fingers tight as ivy on her shoulders,
A light left burning for her in the kitchen.
And heading back for home, the summer's
Freedom dwindling night by night, the air
All moonlight and a scent of hay, policemen
Swung their crimson flashlamps, crowding round
The car like black cattle, snuffing and pointing
The muzzle of a sten-gun in my eye:
'What's your name, driver?'
                                           'Seamus . . .'
                                                               Seamus?

-Seamus Heaney, April 13, 1939 - August 30, 2013.