Boghadair says with mindspeech.  "Whoa there.  Dwarves are still alive and in the world.  But the entrance to this cave has been lost until recently.  The dwarves, gnomes, and humans that once used this cave on a daily basis were killed in an Orc attack many years ago.  So long ago, that this cave and it's forge has become almost a legend, or fairy tale of what used to be.  We have no interest in tricking you.  Just trying to let you know that the wizard that once summoned you is most likely dead.  You can continue to guard these treasures if you wish, but I fear that particular wizard will not return to eventually release you.  I'll assume that since he summoned you to do this job, that you are quite powerful, and can do so easily."

Boghadair continues using mindspeech to speak to the creature, "You mentioned there is a giant roaming these caves as well as the wizard that's been harassing you?  Can you tell us which direction the giant went, and what type of giant it was?  We're just a small group of people, and aren't interested in running into trouble.  We just want to find the brother of this dwarf and get him to safety."  

 So I guess this it for me.  Time to head back to my plane of existence.  Some parting advice.....

Get out of here before you become the undead.  Lots of dark creatures roaming around.  Take care of your Dwarf friend ... he has a good heart.   Oh yeah... the forge still has some magic left in it.  Good luck.

A narrow ledge overlooks a large cavern that houses a surging, seething body of water. The rhythmic booming heard throughout the mines is louder here. At regular intervals, a fresh surge of water funnels into this chamber and slams against the wall just below the ledge. The echo suggests that this cave might be one arm of a much larger cavern to the northeast.

The structural damage and the skeletal remains in this area are evidence of the destructive spell battle fought here centuries ago when the orcs and their mercenary wizards stormed the mines.

Glittering minerals in the ceiling of this large cavern catch the light and send it back to create the impression of a starry night sky. Dozens of skeletons — many crushed under fallen debris — are scattered across the floor.

The cave is large enough that it contains two freestanding structures. Each of these stone buildings is proportioned for human use, as opposed to the dwarf-sized doorways and furnishings you’ve seen elsewhere in the mines. Both structures have battered and blackened masonry walls, their double doors cracked and scorched.
The cavern is divided by an escarpment, into which a flight of stairs has been cut. Passages lead out of this area to the north, south, and west.

Brazier of Green Flame. A successful Intelligence check identifies the brazier as the source of the magic that suffuses the surrounding caverns. This magic has waned over the years, to the extent that it can no longer be harnessed to permanently enchant magic items. However, any nonmagical weapon or armor bathed in the green flame for at least 1 minute becomes a +1 weapon or +1 armor, respectively, for 1d12 hours. The brazier cannot be removed from the Forge of Spells.

Northern Room. This small room is a separate workspace, where items being prepared for enchantment were polished, lacquered, and otherwise finished. Like the main workshop, it has been almost completely destroyed.

Treasure

On the worktable in the southeast corner of the room are the last items the spectator was charged to protect: Lightbringer and Dragonguard.

Lightbringer. This +1 mace was made for a cleric of Lathander, the god of dawn. The head of the mace is shaped like a sunburst and made of solid brass. Named Lightbringer, this weapon glows as bright as a torch when its wielder commands. While glowing, the mace deals an extra 1d6 radiant damage to undead creatures.

Dragonguard. This +1 breastplate has a gold dragon motif worked into its design. Created for a human hero of Neverwinter named Tergon, it grants its wearer advantage on saving throws against the breath weapons of creatures that have the dragon type.