Free Summer of the Sea Serpent: A Merlin Mission by Mary Pope Osborne

J ack was sitting on the porch reading the newspaper. It was a warm summer day, but the porch was shady and cool.
    Annie poked her head out of the screen door. “Hey, Mom says she’ll drive us to the lake this afternoon,” she said.
    Jack didn’t raise his eyes from the weather page. “Did you know today is the summer solstice?” he said.
    “What’s that?” asked Annie.
    “It’s the official first day of summer,” saidJack. “There’s more daylight today than on any other day of the year.”
    “Cool,” said Annie.
    “Starting tomorrow, the days will get shorter and shorter,” said Jack.
    A loud screech came from overhead.
    “Look,” said Annie, “a seagull!”
    Jack looked up. A large white gull was circling in the bright noon sky. “What’s he doing here?” asked Jack. “The ocean’s two hours away.”
    The gull swooped down and screeched again.
    “Maybe he’s a messenger from Morgan or Merlin,” said Annie. “Maybe one of them sent him to tell us the tree house is finally back.”
    Jack’s heart began to pound. He put down the newspaper. “You think so?” he asked.
    Jack and Annie hadn’t seen the magic tree house since their Merlin Mission to a haunted castle last Halloween. Jack had begun to worry that the tree house might never come back.
    “Look, he’s flying toward the woods,” said Annie.
    Jack jumped up. “Okay,” he said. “Let’s go.”
    “We’ll be back soon, Mom!” Annie called. Then she and Jack dashed across their yard. They ran down their street and into the Frog Creek woods.
    The shady woods were dappled with sunlight. The air smelled fresh and clean. Jack and Annie hurried past the leafy trees, until they came to the tallest oak. High in the oak branches, the magic tree house was waiting for them.
    “Wow,” Jack and Annie said together. The tree house looked exactly the same as when they’d last seen it.
    Annie grabbed the rope ladder and started up. Jack followed. When they climbed inside the tree house, no one was there.
    “Look, our Royal Invitation is still here,” said Annie. She picked up the card that had taken them to Camelot on Christmas Eve.
    “And our leaf from Merlin is still here,” said Jack. He picked up the yellow autumn leaf that had sent them on their Halloween mission.
    “This is new,” said Annie. She picked up a pale blue seashell. The shell was shaped like a small fan. There was writing on it.
    “Hey, this looks like Merlin’s handwriting!” said Annie. “We must be going on another mission for Merlin!” She read aloud the message from the magician:

    Annie looked up. “What rhyme?” she said.
    “Let me see.” Jack took the shell from her and turned it over. On the other side was a poem. Jack read the poem aloud:
    Before night falls on this long summer day,
    A shining sword must find its way
    Into your hands and out of the gloom—
    Or Camelot’s king shall meet his doom.
    To begin your quest for this Sword of Light,
    Call for the help of the Water Knight.
    Then pass through the Cave of the Spider Queen—
    “Spider Queen?” Annie interrupted. She frowned. Spiders were about the only thing she was afraid of.
    “Don’t think about it now,” said Jack. “Let’s keep going.” He read on:
     … pass through the Cave of the Spider Queen
    And swim with a selkie clothed in green.
    Enter the Cove of the Stormy Coast,
    Dive ’neath the Cloak of the Old Gray Ghost—
    Jack stopped reading. “Old Gray Ghost?” he said.
    “Don’t think about it now,” said Annie. “Keep going.”
    Jack read more:
    Answer a question with love, not fear.
    With rhyme and sword, your home is near.
    Both Jack and Annie were silent for a moment. “That’s a lot to do before nightfall,” Jack finally said.
    “Yeah,” said Annie, “and I’m a little worried about the spider part.”
    “And the ghost part,” said Jack.
    “Hey,” said Annie, “if we’re going on another Merlin Mission, I’ll bet Teddy will come with us! He can help