Edgar Wallace 
The Missing Million [EPUB ebook] 

‘YOU’VE dropped a flower, sir, ‘ said the beef-eater. Detective-Inspector James Sepping blushed and looked down guiltily at the three violets that lay on the gravelled parade ground.
He did not look like a detective, and seemed too youthful to hold any such exalted rank. He had the appearance of an athletic young man about town.
‘No— don’t pick them up, unless it is against the regulations of the Tower of London to drop flowers around. They look good there.’
The burly Yeoman of the Guard, in his quaint sixteenth century dress, fingered his grey beard and looked suspiciously at the visitor. Jimmy Sepping appeared to be perfectly sober.