“Know you a poison,” asked Marcia, “that will not harm one who merely tastes it, but will kill whoever drinks a quantity?  Something without flavor?  Something colorless that can be mixed with wine?  Know you a safe poison, Galen?”

“Aye—­irresolution!” Galen answered.  “I will not be made a victim of it.  Who shall aspire to the throne if Commodus dies?”

“Pertinax!”

Pertinax looked startled, stroking his beard, uncrossing his knees.

“Then let Pertinax do his own work,” said Galen.  “Rome is full of poisoners, but hasn’t Pertinax a sword?”

“Aye.  And it has been the emperor’s until this minute,” Pertinax said grimly.  “Galen tells us Commodus is mad.  And I agree that Rome deserves a better emperor.  But whether I am fit to be that emperor is something not yet clear to me.  I doubt it.  Whom the Fates select for such a purpose, they compel, and he is unwise who resists them.  I will not resist.  But let there be no doubt on this point:  I will not slay Commodus.  I will not draw sword against the man to whom I owe my fortune.  I am not an ingrate.  Sextus lives for his revenge.  If you should ask me I would answer, Sextus planned this murder in the tunnel and the blow was meant for Commodus himself.  I am inclined to deal with Sextus firmly.  It is not too late.  There is a chance that Commodus, deprived now of his opportunities to make himself a spectacle, may bend his energies to government.  Madman though he is, he is the emperor, and if he is disposed now to govern well, with capable advisers, I would be the last to turn on him.”

“If he will be advised by you?” suggested Marcia, her accent tart with sarcasm.  “What will you advise him about Sextus?”

“There are plenty of ways of getting rid of Sextus without killing him,” said Pertinax.  “He is a young man needing outlets for his energy and fuel for his pride.  If he were sent to Parthia, in secret, as an agent authorized to penetrate that country and report on military, geographical and economic facts—­”

“He would refuse to go!” said Galen.  “And if made to go, he would return!  O Pertinax—!”

“Be quiet!” Pertinax retorted irritably.  “I will not submit to being lectured.  I am Governor of Rome—­though you are Galen the philosopher.  And I remember many of your adages this minute, as for instance:  ’It is he who acts who is responsible.’  To kill an emperor is easy, Galen.  To replace him is as difficult as to fit a new head to a body.  We have talked a lot of treason, most of it nonsense.  I have listened to too much of it.  I am as guilty as the others.  But when it comes to slaying Commodus and standing in his shoes—­”

Marcia interrupted.

“By the great Twin Brethren, Pertinax!  Who can be surprised that Flavia Titiana seeks amusement in the arms of other men!  Does Cornificia endure such peasant talk?  Or do you keep it to impose on us as a relief from her more noble conversation?  Dea Dia!  Had I known how spineless you can be I would have set my cap at Lucius Severus long ago.  It may be it is not too late.”