Reid mentions "Herzog and Shermantine" - as in Loren Herzog and Wesley Shermantine - murderers known as the "Speed Freak Killers". The two methamphetamine (speed) addicts were convicted of killing at least 4 people between 1984 and their capture in 1999, though they may be responsible for 68 more deaths. Shermantine is on death row in San Quentin. Herzog committed suicide in prison in 2012.
Final appearance of Kevin Lynch (Nicholas Brendon). Although he does make an appearance in a flashback in the season 15 finale.
(Disclaimer, this is simply a summary, absent of opinion.)
The 9 Circles of Hell in Dante's Inferno are:
1. Limbo, a place of loss, close to Heaven but forever shut out. For those who lived righteously but had no faith in Jesus.
2. Lust. Where the damned endure raging wind storms, allowing neither sleep nor rest.
3. Gluttony. Gluttons are bogged down in freezing slush, in an unceasing rain, and guarded by Cerberus.
4. Greed. The greedy, split into those who spent too freely of others wealth, and those who hoarded wealth, fight for eternity using great weights upon their chest, crushing them with the weight of the material possessions they once desired. (Many men of the cloth were in this circle.)
The fifth circle, the River Styx, is the divide between the upper and lower levels of Hell.
5. Wrath. The River Styx, where wrathful souls fight each other for eternity, never able to leave the battle or the river.
The sixth level is the first of the true punishment circles.
6. Heresy. Those who's beliefs went against the "core of Christianity" were trapped in burning tombs. (Dante encountered a Pope in there.)
7. Violence. There are 3 circles within the seventh circle;
I. Violence against neighbours (harm to their fellow man). The soul is submerged in a river of boiling blood and shot with arrows by Centuars if they try to rise too far out of the river.
II. Violence against self. The souls are transformed into "dead" withered trees, that still bleed, and fed on by Harpies.
III. Violence against God or nature. This circle was a land of burning sand and flaming rain, where blasphemers and sodomites were punished.
8. Fraud. Known as Mailbuch, meaning Evil Ditches, was 10 separate ditches (Bolgia) joined by bridges. Each Bolgia was populated by a different kind of fraudster;
I. Panderers and seducers are whipped by Demons.
II. Flatterers are buried in excrement.
III. Simoniacs (those who sold Church office or fake relics for profit) are given a reverse baptism. Put headfirst into a hole the size of a baptismal font and their feet set alight.
IV. Sorcerers and false prophets have their heads turned backwards, as they claimed to see the future they will only ever see what is behind them. The ground is sodden with the tears that blind them.
V. Corrupt politicians are submerged in boiling tar. Demons attack any who try to escape.
VI. Hypocrites, unlike the other souls, are clothed, in gilded robes lined with lead to show the duplicity of their nature and weigh them down in their endless journey.
VII. Theives are attacked by snakes, while they themselves transform into snakes.
VIII. Those who gave false counsel, or counseled others to behave fraudulently are consumed by brilliant flames. (The look like a swarm of fireflies.)
IX. Those who divided others with their deceit are also divided. A demon slashes at them with a sword, mutilating and dismembering as they pass, their wounds heal as they walk the circle, just to return to the demon.
X. Falsifiers; perjurers, alchemists, counterfeiters, impersonators, are subjected to a range of diseases, from leprosy to fevers depending on their sin.
9. The final circle is revered for treachery. And again divided by severity, each section is named after a sinner who personified the sin for that area; Caina, after Cain who killed a relative. Antenora, after the Trojan Prince who betrayed his country. Ptolomea, after Ptolemy who murdered a trusting guest. And finally the silent centre, Judecca, after Judas Iscariot who betrayed his Lord. The souls are completely encased in ice as their hearts were in life.