Say what you like about Edinburgh's Grid Iron theatre company, it is, to quote Lady Macbeth, "not without ambition".

Having in recent years walked audiences around a Princes Street department store and Edinburgh International Airport, it is now taking us to another planet - well, the Edinburgh International Climbing Arena at Ratho, to be honest - but it doubles credibly as the induction centre of the space colony known as New Earth.

At the outset of Leaving Planet Earth, the company's new show for the Edinburgh International Festival, we somewhat incredibly jump from Old Earth, ravaged by war, ecological disaster and social unrest, to the new planet, while on board a coach.

However, Grid Iron makes good use of the road journey, with film informing us of the catastrophes we are leaving behind (including Jon Snow of Channel 4 News, redeeming himself after his recent, agriculturally Cornish attempt to impersonate a Scouser).

Our induction, which takes us to various corners of the arena, is punctuated by a developing drama among the leading lights of the colony. The design elements - from the video and sound work to the reassuringly naff costumes and the shallow eclecticism of the Old Earth Museum - are a delight, even if the script (by co-directors Catrin Evans and Lewis Hetherington) is more variable.

To give away the twist of this sci-fi thriller would be a crime worthy of expulsion into space in a solitary confinement pod. Suffice to say that the script would benefit from less soap opera-style chat and more of a focus upon the chilling mission to which Meeka, a military pilot, has been assigned.

Whatever its shortcomings, however, this piece succeeds through a combination of its clever choice of venue, impressive theatrical logistics and an occasionally absorbing narrative.

More ambitious, even, than Grid Iron's massive project is Ulysses, director Andy Arnold's staging of James Joyce's great novel for Glasgow's Tron theatre company. Using Dermot Bolger's beautifully crafted adaptation (carefully and coherently selected from the fiction, with a palpable love for the sensuousness and abundance of Joyce's language), Arnold's lovely production (first staged in Glasgow and Ireland in the autumn of last year) richly deserves this Fringe revival.

There is tremendous pleasure, and no little stimulation (be it intellectual, emotional or erotic), to be had in giving oneself over to the tremendous atmosphere of the piece. Whether it be Muireann Kelly's Molly Bloom (fabulous in her jovial, unembarrassable carnality) or Paul Riley's Citizen (a one-eyed monster risen from the swamp of English oppression and Celtic mythology), the production makes a joyous parade of Joyce's genius for character.

There is, of course, no Ulysses without the wonderful, hairline-cracked humanism of Leopold Bloom himself, and Jean-Paul Van Cauwelaert leads a universally excellent cast with a magnetic, gorgeously comic performance. By turns self-effacing, stridently principled and diffident in his mild sexual deviance, he seems to have been born to be Bloom.

Add to this the outstanding set and costume design by Charlotte Lane (as brilliant in its theatrical utility as in its perfect, vertiginous period aesthetic), Sergey Jakovsky's superbly appropriate lighting and Ross Brown's almost imperceptibly well-attuned sound, and you have a truly remarkable theatre presentation of a novel long considered to be unstageable.

There is a similarly compelling aesthetic at work in Tales Of Magical Realism, a beautifully constructed piece by Luxembourgish artist Sven Werner, revived here by Glasgow-based company Cryptic. Inspired by Werner's own film Oculista (a tantalising excerpt is included in the show), the work sits perfectly within the extraordinary, plethoric programme of Summerhall.

A delicate yet robust piece, it combines promenade theatre with film, fictional narrative, cycling and the Victorian peepshow. Simultaneously gothic and modern, Romantic and grotesque, this utterly absorbing art work reminds one, by turns, of the film work of Jean-Pierre Jeunet and Marc Caro (creators of the 1991 movie Delicatessen), the writings of Edgar Allan Poe, the performance and songs of The Tiger Lillies, the film music of Yann Tiersen, and the movie soundtracks of Nick Cave and Warren Ellis.

Remarkable for the consistency of its aesthetic, achieved despite (or perhaps because of) its multiplicity of forms, Tales Of Magical Realism is a delicious antidote to the vulgar banalities of so much of our mass culture.

Steven Berkoff, who is never short of a scathing attack on aspects of popular culture, no doubt considers his latest play An Actor's Lament to be another antidote to what he once memorably called "money-motivated mulch for morons". Sadly, it is not; and so, having recommended the play in my festival tips three weeks ago, I owe you, dear reader, an apology.

Berkoff's talents, both as writer and actor, are undeniable. However, this verse play about the theatre business (particularly the London biz) is lazy, contemptuous and surprisingly unfunny.

Stereotypes abound in this three-hander in which, predictably, Berkoff seeks to distinguish himself (the muscular, warrior actor) from the effete luvvies (cue dubious, prancing caricature) of London's Theatreland. It is little wonder that, as they perform another mock-Lecoq mimed cigarette extinction, Berkoff's co-stars Jay Benedict and Andree Bernard seem so awkward in their roles.

There is no insight or, for that matter, depth (be it intellectual or emotional) to distract one from the unexpected dreariness of Berkoff's rhymes. Equally banal are the play's fevered egos, complete with inevitable "love them, hate them" attitudes to both the critics and fellow theatre makers. Lamentable indeed.