Ancient Ruins Expedition (6) - Mysterious Flute

What they found behind the painting was a safe, locked with some sort of combination of numbers.

The student's frustration was palpable. "We don't know the combination," he groaned, kicking at the ornate rug that lay before the safe. "This is useless!"

William stepped forward, his curiosity piqued. "Let me take a look."

The safe, though ancient, appeared similar to those he had encountered in his own time. He examined the dial, the intricate carvings that adorned its surface, searching for any clue to its combination.

"I can find the combination for you," the demonic sword's voice whispered in his mind.

William, though growing accustomed to the sword's unexpected assistance, couldn't help but feel a surge of skepticism.

"Are you sure?" he asked mentally. "And how, exactly, do you propose to do that?"