But before they could say anything more, Lieutenant Ekman had returned from inspecting the lighthouse with Karen's father, and was calling to Gerda that it was time for them to start for Luleå.
"Good-bye," the two little girls said to each other, and Karen went down to the landing-place to watch the launch steam away.
Gerda stood quietly beside the rail, looking back at the island, long after Karen's rainbow skirt and the lighthouse had faded from sight.
"I will give you two öre for your thoughts, if they are worth it," her father said at last.
"I was thinking that it will make Karen sad to hear of my good times this winter," Gerda told him.
"She will like to have your letters to think about," replied Lieutenant
Ekman cheerfully. Then he pointed to a little town on the shore ahead.
"There is Luleå," he said. "You will soon be travelling on the railroad
toward Mount Dundret and the midnight sun."
But although Gerda was soon speeding into the mysterious Arctic regions, she could not forget her new friend in the lonely lighthouse.
CHAPTER V
CROSSING THE POLCIRKEL
"Polcirkel, Birger, Polcirkel!" cried Gerda from her side of the car.