The Rose's Syringer unique weapon can be obtained at the "Top Of The World" resort, which is located in the center of the map in the Savage Divide region. The quest for the special syringer is given by a Raider Robot named "Rose" on the top floor of the resort. Talk to Rose, and she will send you on three Raider faction quests: "Signal Strength", "Flavors Of Mayhem", and "Keys To The Past". Complete all her quests to get Rose's Syringer. Most syringers are not too useful, but this syringer turns any enemy shot with it extremely powerful for 60 seconds, and then extremely weak for 60 seconds. As long as you can survive the first 60 seconds, even high-level enemies can then easily be killed. This allows Level 10-20 players to kill Level 40-50 enemies. Note: While at the "Top Of The World" resort, you can also find a Vault-Tec Bobblehead on the Mezzanine Level, on a speaker near the elevator exit.