Three exhibitions this week show how unusual circumstances have intersected with the work of three notable artists to give a special twist to their familiar work.

The most exceptional circumstances concern the work of Stephen Bambury and the result is a fine exhibition at the Jensen Gallery until the end of October.

The painter was invited to take up a residence in Slovenia under the auspices of the Keleia Foundation of Ljubljana.

He intended to use the time to paint in his long-established manner on aluminium panels but to use colour influenced by early Renaissance painting in Siena and Florence.

He prepared the panels in New Zealand but they were misdirected and lost somewhere in Bosnia.

With his familiar working practice disrupted, Bambury turned to a small stack of stone tiles he found in the courtyard of his accommodation. They were old, battered and weathered.

He set them up in pairs and marked and painted them with his usual geometric shapes.

The fascinating results are now on display as a unique group of works. The tiles are immediately recognisable as stone. This is often emphasised not only by the rugged surface but also by blunted edges and sometimes by broken corners.

Yet the markings of pigment wax and malleable metals have endowed them with grace and magic.

They are beautiful pieces that have a resonance the artist's recent work has lacked perhaps simply because his geometrics had become too familiar.

These works have an added dimension. It is history. They are made precious because they carry the feeling of the past with them as fragments of history.

The preciousness is emphasised by the frequent use of gold leaf. Some of the most striking works use gold leaf worked into the texture of the stone against a red background.

It recalls early Italian painting where a red ground was applied before gold leaf was attached. In such work the gold is often rubbed and the red ground shows through.

The works are like small pieces, little geometric remains of a damaged but once-wonderful fresco. In some of the work, such as Sienska 13, which has dark markings, is a hint of fire in their past.

Matched in pairs, similar but separate, the works have great individuality and presence. It is modern abstract art but it is touched with the magic of rituals of the past.

At Whitespace in Crummer St, outstanding expatriate artist Alexis Hunter has a show called Amphetamine Queen and Other Spirits until the end of the month.

One feature of her work has been invented animals and birds that symbolise states of mind and often take the form of devils and spirits filled with wicked energy.

The best of these convey a sense of female, assertive energy pushed by instinctive drives. She has done many of these and this show feels as if the concept has been overworked.

Her Flax Spirits and even her firework Amphetamine Queen are spectacular but more than a bit obvious. They certainly cannot compete with three drawings called Spirit, which by keeping an eye on the subject, convey a lively sense of character.

But the circumstance that transforms her work in at least one painting is the recent attacks on London. Terrorist takes her instinctive wild animal and, gender issues forgotten, makes a fierce raptor of it with threatening eye, sharp beak and horrid spurs.

It looks down on a sweep of devastation. Its fierce appetite for death and destruction and its driven energy are powerfully conveyed by the form and brushwork.

It is not specific to attacks on tubes or buses but convincingly evokes powers at work that are equally present in Leeds, where the strange creature hovers over that racially racked, polluted city.

The rest of the work is effective but pale by comparison but Hunter's invention and skill comes deliciously to the fore in one other circumstance.

When she was last in New Zealand she decorated a number of vases and jugs. She exactly fits the fat rotundity of pigeons to the jug shape, and one of her lively devils, treated humorously here, gives distinction to a water jug. They are lovely painted ceramics with a little spin of oddity.

At the Sue Crockford Gallery, the special circumstance of Julian Dashper's work is that it is hung in close juxtaposition with the work of the late Gordon Walters and gains by the proximity. Both artists work with extreme abstract simplicity and generally in black and white.

Dashper's work relies on concept as well as design. A characteristic work is a screen-print, which is a design of circles but we are expected to recognise that the outer black circle is based on a vinyl record; the inner circle is a CD and the two little circles in the centre are based on the holes in the records.

Importantly, the image is derived from found objects. The result is visually dead but conceptually alive. It lacks the tense interplay of shapes that characterise the best of Walters but it takes a philosophy of art to a logical extreme. It works well only once in No 17, a two-piece work in canvas and hardboard.