Old scifi book: detective, alien conspiracy, change appearance machine, huge brain in space ship, alien communicates by flashing lights from stomach

Question

I am looking for an old book. People can use a machine to change appearance and genetically modify themselves. The main character is a detective or cop, he follows a suspect into the sewers and finds out it has changed into a savage creature, black pit.

Eventually he follows the trail to a huge space station or spaceship, inside the ship is a giant brain, needed to run calculations.

This brain is communicating with the mastermind of a conspiracy who has found out aliens are alive. He turned himself into an alien. The aliens are much smarter than humans, and communicate by flashing colors and lights from abdomen. He sends a message that has huge amounts of information somewhere by camera and is tired aftwards.

Answer 1

Sight of Proteus., and review.

By Charles Sheffield.

A three novel series. Part two is Proteus Unbound, part three is Proteus in the Underworld. The book series involves a minor amount of space travel towards the end. Parts appeared in various: Amazing, Galaxy.

^{Danny Flynn, Danny Flynn.com commercial site, 2017, fair usage.}

Alternative cover-art:

^{Original novelisation art, copyright unknown, via review website 2022. Fair usage.}

The main protagonist, a man by the name of Behrooz Wolf is a Form-Change expert and an investigator for the Office of Form-Change.

Complicating matters greatly is the emergence of Form Change, which through simple biofeedback and other measures allows people to control their body from its appearance (and gender) to subtle elements of health itself. While experimenting with Form Change is fairly dangerous (and some of the alternate forms have life-span multipliers of .2) the average human can expect to live about a century, perhaps as long as 120 years; increased lifespans only add to the population problem.

The description then goes on to the point of discovery of the "alien" with odd DNA.:

When an over-eager student decides (fairly illegally) to practice chromosome identification on a sample from the organ banks, he discovers that the donor appears in no records, something that should not be possible in this highly regulated world. Bey and John investigate and despite the efforts of the prime suspect, another one of this world’s well-connected masters, uncover a vast and old conspiracy involving daring, often lethal and definitely illegal experiments in Form Change.

The third novel, two of the characters have transformed into the alien form (with a society shattering life ratio of 3.5), and communicate at one point by data-link using their chests, modulating the colours and shapes of the light they are able to generate on their chests down to the pixel, communicating vast amounts in a short time. They call this "burst mode".

The "Huge brain in spaceship" part was Pearl, a converted hollow asteroid containing the ever-transforming female occupant, sent on an interstellar journey of exploration. She's older than she looks.