Forever by Robert Sheckley. Short summary

5 seconds

Denison invented an immortality serum. He was captured by an organization unwilling to spread the elixir to the masses. Put him with other scientists who had created a similar elixir. The scientists escaped, staging a riot.

1 minute

Scientist Denison invented an immortality serum. He went to the Patent Office. Two men approached him on the subway and, at gunpoint, demanded that he hand over the elixir.

Denison tried to escape, but the men caught up with him. Then he drank the elixir. The men led him to the head of the secret organization.

He told the scientist that the elixir had been invented long ago, but it was being kept quiet because the world was not ready for it.

Denison was offered cooperation, but he refused. Then he was sent into confinement.

There he met all the scientists who had created the elixir long before him. They organized the Eternity Club.

After 137 years, they escaped their captors and revealed their plot to the government. Those were punished.

Then the Eternity Club went underground, fighting to overthrow the ruling immortal elite and spread the elixir to the population.