Question: what is the body of water by the birthplace of the author of The Iron Crew?

full_context: Document 1: Boston: Boston is surrounded by the "Greater Boston" region and is contiguously bordered by the cities and towns of Winthrop, Revere, Chelsea, Everett, Somerville, Cambridge, Newton, Brookline, Needham, Dedham, Canton, Milton, and Quincy. The Charles River separates Boston from Watertown and the majority of Cambridge, and the mass of Boston from its own Charlestown neighborhood. To the east lie Boston Harbor and the Boston Harbor Islands National Recreation Area (which includes part of the city's territory, specifically Calf Island, Gallops Island, Great Brewster Island, Green Island, Little Brewster Island, Little Calf Island, Long Island, Lovells Island, Middle Brewster Island, Nixes Mate, Outer Brewster Island, Rainsford Island, Shag Rocks, Spectacle Island, The Graves, and Thompson Island). The Neponset River forms the boundary between Boston's southern neighborhoods and the city of Quincy and the town of Milton. The Mystic River separates Charlestown from Chelsea and Everett, and Chelsea Creek and Boston Harbor separate East Boston from Boston proper.
Document 2: The Crimson Patch: The Crimson Patch, first published in 1936, is a detective story by Phoebe Atwood Taylor which features her series detective Asey Mayo, the "Codfish Sherlock". This novel is a mystery of the type known as a whodunnit.
Document 3: Dead Ernest (novel): Dead Ernest is a novel that was published in 1944 by Phoebe Atwood Taylor writing as Alice Tilton. It is the seventh of the eight Leonidas Witherall mysteries.
Document 4: The Adventures of Leonidas Witherall: Based on the novels of Phoebe Atwood Taylor (writing as Alice Tilton), the 30-minute dramas were produced by Roger Bower and starred Walter Hampden as Leonidas Witherall, a New England boys' school instructor in Dalton, Massachusetts, a fictional Boston suburb. Witherall, who resembled William Shakespeare, is an amateur detective and the accomplished author of the "popular Lieutenant Hazeltine stories."
Document 5: Boston: Boston is surrounded by the "Greater Boston" region and is contiguously bordered by the cities and towns of Winthrop, Revere, Chelsea, Everett, Somerville, Cambridge, Watertown, Newton, Brookline, Needham, Dedham, Canton, Milton, and Quincy. The Charles River separates Boston from Watertown and the majority of Cambridge, and the mass of Boston from its own Charlestown neighborhood. To the east lie Boston Harbor and the Boston Harbor Islands National Recreation Area (which includes part of the city's territory, specifically Calf Island, Gallops Island, Great Brewster Island, Green Island, Little Brewster Island, Little Calf Island, Long Island, Lovells Island, Middle Brewster Island, Nixes Mate, Outer Brewster Island, Rainsford Island, Shag Rocks, Spectacle Island, The Graves, and Thompson Island). The Neponset River forms the boundary between Boston's southern neighborhoods and the city of Quincy and the town of Milton. The Mystic River separates Charlestown from Chelsea and Everett, and Chelsea Creek and Boston Harbor separate East Boston from Downtown, the North End, and the Seaport.
Document 6: The Iron Clew: The Iron Clew is a novel that was published in 1947 by Phoebe Atwood Taylor writing as Alice Tilton. It is the eighth and last of the eight Leonidas Witherall mysteries.
Document 7: The Clue of the Broken Locket: The Clue of the Broken Locket is the eleventh volume in the Nancy Drew Mystery Stories series. It was first published in 1934, and was written by Mildred Benson under the pseudonym Carolyn Keene.
Document 8: Figure Away: Figure Away, first published in 1937, is a detective story by Phoebe Atwood Taylor which features her series detective Asey Mayo, the "Codfish Sherlock". This novel is a mystery of the type known as a whodunnit.
Document 9: Cold Steal: Cold Steal is a novel that was published in 1939 by Phoebe Atwood Taylor writing as Alice Tilton. It is the third of the eight Leonidas Witherall mysteries.
Document 10: Boston: Boston has an area of 89.6 square miles (232.1 km2)—48.4 square miles (125.4 km2) (54.0%) of land and 41.2 square miles (106.7 km2) (46.0%) of water. The city's official elevation, as measured at Logan International Airport, is 19 ft (5.8 m) above sea level. The highest point in Boston is Bellevue Hill at 330 feet (100 m) above sea level, and the lowest point is at sea level. Situated onshore of the Atlantic Ocean, Boston is the only state capital in the contiguous United States with an oceanic coastline.
Document 11: Charles River Reservation Parkways: The Charles River Reservation Parkways are parkways that run along either side of the Charles River in eastern Massachusetts. The roads are contained within the Charles River Reservation and the Upper Charles River Reservation, and fall within a number of communities in the greater Boston metropolitan area. The Charles River parks extend from the Charles River Dam, where the Charles empties into Boston Harbor, to Riverdale Park in the West Roxbury neighborhood of Boston. Most of the roadways within the parks are listed on the National Register of Historic Places as a unit, although Storrow Drive and Memorial Drive are listed as part of the Charles River Basin Historic District.
Document 12: The Lonely Silver Rain: The Lonely Silver Rain (1985) is the 21st and final novel in the Travis McGee series by John D. MacDonald. The work was published a year prior to the author's death, and was not intentionally the end of the series. It is also notable for the introduction of McGee's daughter Jean, who he unwittingly (but not unwillingly) sired with the now-deceased love interest Puss Killian from the ninth book in the series: "Pale Gray for Guilt". At the end of the book McGee has taken all of his cash in hand except for a few hundred dollars and placed it in a trust fund for his newly met teenage daughter, and needs to go back to work as a "salvage consultant." The author's death prevented any further development of this new character and plot line.
Document 13: Boston: Boston Common, located near the Financial District and Beacon Hill, is the oldest public park in the United States. Along with the adjacent Boston Public Garden, it is part of the Emerald Necklace, a string of parks designed by Frederick Law Olmsted to encircle the city. The Emerald Necklace includes Jamaica Pond, Boston's largest body of freshwater, and Franklin Park, the city's largest park and home of the Franklin Park Zoo. Another major park is the Esplanade, located along the banks of the Charles River. The Hatch Shell, an outdoor concert venue, is located adjacent to the Charles River Esplanade. Other parks are scattered throughout the city, with the major parks and beaches located near Castle Island; in Charlestown; and along the Dorchester, South Boston, and East Boston shorelines.
Document 14: The Cut Direct: The Cut Direct is a novel that was published in 1938 by Phoebe Atwood Taylor writing as Alice Tilton. It is the second of the eight Leonidas Witherall mysteries.
Document 15: The Hollow Chest: The Hollow Chest is a novel that was published in 1941 by Phoebe Atwood Taylor writing as Alice Tilton. It is the fifth of the eight Leonidas Witherall mysteries.
ground_truth: Mystic River
sub_queries: The Iron Clew >> author Answer: Phoebe Atwood Taylor
Phoebe Atwood Taylor >> place of birth Answer: Boston
Which is the body of water by Boston ? Answer: Mystic River