Don acted like a lightning flash. With a thrust out of his arms he sent Pen reeling backwards. She fell in the sand. At the same instant Don dived low through the bushes and caught the other man around the legs. He measured his length in the sand. It was so quick that he did not even fire. The pistol flew out of his hand. Pen following a blind instinct, scrambled on hands and knees and secured it.
Don had flung himself on the other man, and they were struggling furiously and silently in the sand. Don kept on top. When Pen's eyes were able to distinguish between them, she saw that Don was planted on the other man's chest, holding one of his arms down with one hand, and pressing his other hand over the man's mouth. With his free hand the man struck ineffectually up at Don's body, or tried in vain to pull away the hand that covered his mouth. His legs were thrashing wildly.
"Something to gag him with," panted Don.
Pen tore off her sun-bonnet and rolling it up with the strings out handed it over. She sat on the man's right arm, when Don was obliged to release it. Somehow Don managed to force the twisted roll of cotton between his teeth, and with Pen's aid, passed the strings under his head and tied the gag with the knots in front. Sepulchral groans issued from beneath it.
"Something to tie his hands and feet!" whispered Don.
Pen, anticipating it, already had her apron off. She managed to tear off the band, which with the strings attached, made a useful lashing. Between the two of them they got the struggling man turned over, and finally got his wrists tied behind him. With the rest of the apron they bound his ankles together. Don rolled his coat around the man's head to stifle his groans, and they stood up and looked anxiously up and down the beach. They were about half way between the lighthouse and the tents. Nothing stirred in either direction.
Don looked down at the helpless figure. "Who do you suppose it is?" he asked.
"Keesing, one of the detectives," said Pen. "I recognized his voice. He must have followed me down here ... But I don't see how he could."
Don shook his head. "More likely Pardoe—the man you ran into here, told him something and he came snooping around just on a chance. I gave myself away with my own talk."
They were silent for a moment. Both were thinking of the same thing.