Bertie Wooster - a character created by PG Wodehouse, the English humorist.  Scene 7

Buck's fizz - mimosa, a drink made with orange juice and champagne.  Scene 2

Cenotaph - a memorial to fallen soldiers of two world wars and often steeped in wreaths.   Whitehall is the wide ceremonial avenue leading from Parliament Square the half a mile to Trafalgar Square.  It is lined on both sides with Government offices, includng the Treasury, the Foreign, Commonwealth and Home Offices, and about half way along, Banqueting House where Charles I was beheaded in 1649. Towards it's southern end, the Cenotaph stands in the centre of the road.  Scene 2

Desert Island Discs - a BBC radio show.  Desert Island Discs was created by Roy Plomley in 1942 - and since then has cast away hundreds of celebrities, from stars of stage and screen to eminent politicians.  Initially guests were only allowed to take eight records with them to the mythical island.  Then after about a hundred programmes Roy Plomley also allowed his 'castaways' to pack a luxury - provided it was "an inanimate object purely for the senses which is not going to help you to live". A  few years later, guests were also allowed to choose a book, in addition to The Bible and the complete works of Shakespeare.  Roy Plomley died in 1985 and Michael Parkinson presented about 90 programmes between 1986 and 1988.  Sue Lawley has presented the programme since then.  Scene 2

House of Cards - the name of Henry's play that was performed by Charlotte and Max (Sarah Woodward and Nigel Lindsay).  Scene 1

MCC - the Marylebone Cricket Club, considered the finest cricket site in London, it is commonly referred to as "Lords".  Scene 5

Miss Julie - a play by August Strindberg, Annie and Henry (Jennifer Ehle and Stephen Dillane) read the parts of Miss Julie and Jean.  Scene 4

Mog - sleeping pill.  Scene 4

Nick -  to steal.  Scene 12

Petard - an explosive device, formerly used in warfare to blow in a door or gate, form a break in a wall, etc.;  hoist by or with one's own petard - caught by the very device one had contrived to hurt another.  Scene 11

'Tis Pity She's a Whore - a play by John Ford, Annie and Billy (Jennifer Ehle and Oscar Pearce) play the parts of Annabella and Giovanni.  Scene 8

Three Sisters - a play by Anton Chekov.  Scene 5

Twiglet - dry biscuit, similar to a pretzel stick.  Scene 2