What surprised the boys when the dog barked furiously? - briefly
When the dog began to bark furiously, the boys were surprised to discover that their hidden treasure had been unearthed by a mysterious figure lurking in the shadows.
What surprised the boys when the dog barked furiously? - in detail
The sudden and intense barking of the dog caught the boys off guard, leaving them surprised and perplexed. They had not anticipated such a fierce reaction from their usually calm and friendly pet. The dog's furious barking seemed out of character, prompting the boys to wonder what could have triggered such an unusual response. As they tried to understand the cause behind the dog's behavior, they realized that there might be an intruder or some unknown threat lurking nearby. This realization sent a wave of alarm through them, making their hearts race as they quickly scanned their surroundings for any signs of danger.