Zap!

Angel’s unexpected reaction to Gwen’s powers in Ground State was written in the stage directions as follows:

ZAP! CGI SPARKS leap from her hands, and we go into a SPECIAL FX SHOT: AN INTERNAL-ORGAN VERSION OF ANGEL’S BODY, as we see his SHRIVELLED DEAD HEART CONVULSE, as though zapped with electricity, before FILLING WITH BLOOD and beginning to BEAT. We HEAR: THA-DUMP, THA-DUMP.

Alexa Davalos

Alexa Davalos played Gwen Raiden in the Angel episodes Ground State, A Long Day’s Journey and Players. Of Greek descent, she was born in France on May 28, 1982. She started out as a model, before appearing in the HBO TV film And Starring Pancho Villa as Himself, with Anthony Stewart Head and Antonio Banderas. She has also appeared in The Chronicles of Riddick, The Ghost of F. Scott Fitzgerald, Disturbing the Peace, and starred in the TV show Reunion as Samantha.
Alexa speaks both Greek and French fluently. Her mother is Greek American actress Elyssa Davalos, and her grandfather is actor Richard Davalos.

Gwen Raiden

Gwen Raiden as a child had extraordinary electrical powers which made her unable to touch humans without giving them electric shocks. Unable to cope, her parents offered a generous donation to a school to take her to deal with her unusual and dangerous talents. As she grew older, Gwen began to hire out her electrical talents to the rich as a cat burglar, retrieving rare and priceless items for cash.
She met Angel’s when he attempted to steal the Axis of Pythia - the same artifact she has been assigned to retrieve. During this time she accidentally killed Gunn and subsequently restarted his heart. She later went to Angel when one of her clients, a member of the Ra-tet, was killed by the Beast, and offered her own luxurious apartment as a safe haven for the last surviving member of the mystical group.
She later asked for Gunn’s help to rescue Lisa, whom she said was the kidnapped daughter of a client, although her true motives were later revealed to be less selfless. She and Gunn stole what was in fact L.I.S.A (a Localized Ionic Sensory Activator) which regulates body temperature, heartbeat and body chemistry. Gunn used the device on Gwen to control her electricity. Finally able to touch a human again, Gwen and Gunn made love.

Death to the cast

Many of the main Angel cast have been killed or near death. Angel was killed and vamped in 1753; Doyle was killed in Hero; Gunn was electrocuted by Gwen and revived in Ground State; Wesley’s throat was slashed in Sleep Tight, he was shot in The Thin Dead Line and finally killed in Not Fade Away; Cordelia was comatose for most of season five before dying in You’re Welcome; and Fred was killed when Illyria took over her body in A Hole in the World.

Axis of Pythea

The Axis of Pythea, seen in Ground State, is an ancient power that bridges all dimensions. It was forged from the tripod of the Delphic oracle into a metal arch set into a marble base. It stands approximately two feet high and weighs eighteen pounds. The Axis is said to have been imbued with many mystical qualities, one of which is finding souls or entities across dimensions. Angel stole the Axis from Chandler’s auction house to find Cordelia.

Dinza

Dinza is one of the Eleusian mysteries, the dark demi-goddess of the lost. Only the dead can enter her presence, and those that do, she often traps for eternity. Angel spoke with Dinza in an attempt to find Cordelia in Ground State.

Denzel Washington

Actor Denzel Washington Denzel Washington is referenced a couple of times in Angel. In First Impressions, the gang have the following conversation:

Gunn: “I haven’t bothered to see a movie since Denzel was robbed at the Oscars for Malcom X. Later.” [He leaves]
Wesley: “That was quite a performance.”
Cordelia: “I know! Talk about being wound up to tight.”
Wesley: “No. I mean Denzel.”
Cordelia: “Oh. Well, he’s always great.”
Wesley to Angel: “What about you?”
Angel: “Who doesn’t love Denzel?”

In Ground State and Long Day’s Journey, Gwen calls Gunn “Denzel”.

eBay

Anya buys the last known Urn of Osiris on eBay in Bargaining (Part 1). For those who have been living in a cave, eBay is an online auction house where you can buy just about anything - I mean anything.
In Ground State, Gunn says “But if it’s at an auction house, can’t we, you know, just eBay the thing?” In A Hole in the World, Knox says to Fred of the mysterious sarcophagus, “I couldn’t find any invoice on it. I thought maybe you went crazy on eBay.”

Ground state

The title of the season four Angel episode Ground State comes from a physics term. Wikipedia says of ground state:

The ground state of a quantum mechanical system is its lowest-energy state. An excited state is any state with energy greater than the ground state. The ground state of a quantum field theory is usually called the vacuum state or the vacuum.

If more than one ground state exists, they are said to be degenerate. Many systems have degenerate ground states, for example, the hydrogen atom. It turns out that degeneracy occurs whenever a nontrivial unitary operator commutes with the Hamiltonian of the system.

According to the third law of thermodynamics, a system at absolute zero temperature exists in its ground state; thus, its entropy is determined by the degeneracy of the ground state. Many systems, such as a perfect crystal lattice, have a unique ground state and therefore have zero entropy at absolute zero (because ln(1) = 0).

The condition of an atom, ion, or molecule, when all of its electrons are in their lowest possible energy levels, is called, not excited. When an atom is in its ground state, its electrons fill the lowest energy orbitals completely before they begin to occupy higher energy orbitals, and they fill subshells in accordance with Hund’s rule.

The Graduate

Joyce’s seduction of Xander in Restless is similar to the events of 1967 film The Graduate, starring Dustin Hoffman and Anne Bancroft. Buffy’s line in Into the Woods, “Are you planning to seduce me, Mr. Finn?” is a paraphrase of the famous line from The Graduate, “Are you trying to seduce me, Mrs. Robinson?”
In Angel’s Ground State, Lilah says, “Looks like Connor’s gonna need someone who cares - like a big sister….or hey, Mrs Robinson, if that’s what he’s into.”

X-Men

Buffy creator Joss Whedon is a huge comics fan, particularly the Marvel comic X-Men. His dream came true when, post-Buffy, Joss wrote the Astonishing X-Men comics. The comic has been referenced numerous times in Buffy:

• In No Place Like Home, Riley says, “Giles, you got that Danger Room set up out back?” The Danger Room was a training room in the X-Men.
• In Tough Love, Xander reads an X-Men comic while in the Magic Box.
• In Two to Go, Jonathan says Willow is like the “Dark Phoenix” who was a character in the X-Men comics.
• In Him, Xander calls Spike a “nimrod”. Xander himself was called this by a soldier in Innocence, and Spike called Warren a nimrod in Smashed. Nimrod was a figure in ancient Babylon, and was also an X-Men character.
• In Bring on the Night, Andrew mentions Apocalypse, who was also an X-Men character (”Okay, I know what you’re thinking. Andrew, bad guy. You think I’m a super-villain like Dr. Doom or Apocalypse or The Riddler.”)
• Gwen Raiden in Angel’s season four appears to have been inspired by Rogue from the X Men - the two had great powers which could harm other humans by touch, and had to wear gloves to protect others.
• Joss Whedon has said that the X-Men character Kitty Pryde (AKA Shadowcat) was a large influence for the character of Buffy.

Seen at 15.03 minutes:

In Ground State, Gwen takes the glove off her left hand when she’s at the table with the businessman. She zaps his watch, but when the camera pans away and you see Gwen walking away, the glove is back on.