Strnad and Kane bring Sword of the Atom to a conclusion with issue 4 (Dec 83).
Although he stands a good chance of dying as he leads the rebel attack on the city, the Atom has never felt more alive, or more like himself. He is not missing his life as Ray Palmer in any way.
There was a traitor among the rebels, who had been communicating with the evil advisor plotting to overthrow the king. The idea had been to have the rebels enter the city secretly, then fight on the side of the advisor. The traitor is put to death, but Atom is glad that they will not have to fight their way in.
The advisor has had his plans discovered as well, and the king confronts him about his treachery. The advisor figures its too late to do anything but go forward, so he stabs the king and has his men bring him to the machines. The rebels encounter little resistance, as the people have learned about how the advisor was manipulating the king. Laethwen is brought to her father as he dies.
The advisor turns on the star drive machine, powered by white dwarf star. This threatens to detroy the entire city, and he is not able to safely channel the energy he absorbs from it. Voss kills the advisor with a single shot to the head.
The Atom then steps in to try to stop the machines and save the city. He absorbs the white dwarf star energy, which makes him grow. He loses sight of the city as he grows larger, but hears an explosion before passing out.
Ray Palmer wakes up in a hospital, alive and well. He wants to get back to Laethwen and her people, but has no idea where in the jungle they are located, or even if they survived. Jean Loring is at the hospital to pick him up and bring him back home, but the art makes clear there is still a gulf between them.
It's a good ending, pretty much begging for a continuation, without actually being a cliffhanger. There was no way the events of this miniseries could simply be ignored going forward. And, indeed, there would be a series of Sword of the Atom Specials, beginning the following year, although even before that the Atom would return in Justice League of America, a couple months down the road.