"Oh, boys, you're just in time!" exclaimed Mary, as they were having some lemonade out on the shady piazza. "Aren't they, Grace?"
"In time for what?" Tom wanted to know.
"The dance!" answered Mary. "We're having one to-night. You can stay, can't you, Tom? And you, Ned?" She looked appealingly at Tom.
"Afraid not," he answered. "We have a number of engagements, and our schedule——"
"Oh, Tom Swift!"
Mary's disappointment was so genuine that Tom, who had been a little stiff with her at first, relented and said:
"We haven't dress suits with us."
"It's an informal dance," Grace made haste to say, and after being urged a bit more the two visitors consented to come to the affair that evening. They refused an invitation to dinner, as both Tom and Ned wanted to see how it would be to get their own meal on the electric stove in the House on Wheels.
The dance was a great success. Ned found Grace Winthrop a gracious hostess, and he did not seem to miss Helen much.
In fact, he was having such a good time that it was not until late in the evening that he noticed Tom sitting by himself out on the porch and looking in one of the long windows at the dancing floor. Among the couples foxtrotting about were Mary and a young fellow named Floyd Barton to whom Ned had been introduced.