I Wouldn’t Know Anything About That, Mum

Black-pantsed and white-shirted, starched within a hair’s breadth of “entirely presentable”, I stand just off to one side of the dining room table.
The opening theme of Downton Abbey has been playing on a loop for the last two hours.
I shall hear it until I die.
“It’ll be fun,” Michelle had e-mailed.  “A murder-mystery dinner-party situation out in Medina.  They’re expecting 20.”
The house is absolutely palatial.  Paulie, the chef, has been here for almost half an hour.  In the oven: beef tenderloin, just this side of rare, cut into thick slabs; smoked gouda potatoes rest in chafing dishes alongside jewel-like green beans. Canapes are laid out; flowers, both decorative and edible, are placed alongside them on chilled pewter trays.  
In the time before the guests arrive, I light candles; fill water goblets; open wine bottles; slice strawberries for the Pavlova; fill éclairs; heap fresh, hot bread into linen-lined baskets. 
The dinner party, dressed in clothing fashionable from the 1890s to the 1930s, arrives and, shortly after the cocktail hour, is seated for dinner.
"Ma-MAW," cries the 21-year-old flapper.  Her British accents swings from Cockney to posh, seemingly by the word.  "Oh, maman, how utterly dreadful it is to be so incredibly wealthy.  How I wish I were like the common people.  Footman!  Footman!  I say, guvnuh!"
The man seated across from her rolls his eyes northward where they appear to stick.
"What is this salad dressing?  Cilantro lime?  Oh, yes," she cries.  "One simply must have a dinner party with the cuisine of our newest country, Mexico."  She raises a glass.  
"Oh, by all means," the man across from her drawls rudely.  "Rule Britannica."
The table laughs the laugh of the wine-drunk.  "Ma-MAW," the flapper bleats.  "Is he making fun of me?  Footman!"
Finally, the footman -- a fellow guest of the dinner party forced to eat his dinner in the next room -- ("Even at dinner parties, I can't get away from the !@#$ing kiddie table," he had said, sitting down) -- enters.
"Yes," he says flatly.
"I don't like your attitude," the flapper exclaims petulantly.  "You're fired, you hear me?  Fired!" She raises her wine glass imperiously.  "Fill this before you go."
The evening is saturated with the stuff of the very best parties:  plenty of wine, great food, horrible accents, and devious, conniving servants.
Yes.  While the party-goers drunkenly refer to their murder-mystery character-guide booklets, spilling information hither and yon, I lurk in plain sight.
A woman has been found in the servants’ quarters, murdered.  Her hand is reaching for the butler’s door.
A stable hand finds a woman’s nightgown amongst the horses.
The butler confides to the flapper that yes, he disposed of the weapon used to kill the young woman, but he swears he never hurt her. 
The lady of the house discloses to her mother, between glasses of wine, that the lord of the house has been, this last fortnight, unaccounted for between supper and retiring.
The parson confesses to the doctor that he has been secretly reporting to Her Ladyship on His Lordship’s locations.
His Lordship mentions to the footman that his new shoes are perfect, thank you.
I wait.  Wait for someone to approach me.  After all, who better to ask about the goings-on in a big house than the help?
Alas, the person in a position to know is not consulted. 
And when 10:00 approaches, the hour that the killer is to be revealed, I slip a note under His Lordship’s dessert plate.
“I know what you did in the stables.”