Hackness shook hands thoughtfully with Cynthia Grimfern. There was a slight frown on her pretty intellectual face as she noted his tie.

"There's a large smut on it," she remarked, "and it serves you right."

Hackness explained. He had a flattering audience. He told of the strange happening in Trafalgar Square and the majestic scene on the river. He gave a graphic account of the theory that he had built upon it. There was an animated discussion all through dinner.

"The moral of which is that we are going to be plunged into Cimmerian darkness," Cynthia said, "that is, if the fog comes down. If you think you are going to frighten me out of my evening's entertainment you are mistaken."

All the same it had grown much darker and thicker as the trio drove off in the direction of the Lyceum Theatre. There were patches of dark acrid fog here and there like ropes of smoke into which figures passed and disappeared only to come out on the other side choking and coughing. So local were these swathes of fog that in a wide thoroughfare it was possible to partially avoid them. Festoons of vapour hung from one lamp-post to another, the air was filled with a fatty sickening odour.

"How nasty," Cynthia exclaimed. "Mr. Hackness, please close that window. I am almost sorry that we started. What's that?"

There was a shuffling movement under the seat of the carriage, the quick bark of a dog; Cynthia's little fox terrier had stolen into the brougham. It was a favourite trick of his, the girl explained.

"He'll go back again," she said. "Kim knows that he has done wrong."

That Kim was forgotten and discovered later on coiled up under the stall of his mistress was a mere detail. Hackness was too preoccupied to feel any uneasiness. He was only conscious that the electric lights were growing dim and yellow, and that a brown haze was coming between the auditorium and the stage. When the curtain fell on the third act it was hardly possible to see across the theatre. Two or three large heavy blots of some greasy matter fell on to the white shoulders of a lady in the stalls to be hastily wiped away by her companion. They left a long greasy smear behind.

"I can hardly breathe," Cynthia gasped. "I wish I had stopped at home. Surely those electric lights are going out."