In one of the works made for this exhibition, Tomás Cunha Ferreira uses aluminium foil to cover three parallel drawings, resembling window silhouettes. He adds a layer of grey to make them airtight. Below is drawn a face on the wall, covered with a mask, also made of aluminium, hiding itself. Pequenos Fogos is not about him, but about the work of José Leonilson. Tomás is only a critical agent, a mediating gaze, he is never referred to in any captions, except in the exhibition’s introductory text. His presence is noted in Leonilson’s absence, as if it were a disguised, masked retrospective, where the dialogue fades – a monologue of two voices.

According to the exhibition text, José Leonilson was openly fascinated by maps – I believe he was drawn to the decipherment demanded by the object, to the restlessness of the search for a meaning, an orientation. As his work can be plainly understood from this angle – the will to perceive, to register, creation as one who annotates something, as one who breathes, where the non-object becomes a dignified fact, converted into material, available to be deciphered like the cartographer’s planisphere that represents places where he has not (yet) been. It is an art that comments on something, that withholds thoughts so as not to forget itself, crystallising its random movement, impossible to sustain. It is basic, poetic, straightforward, unavoidable. Drawings are created to be poems, vague texts looking for a helping hand. In Pequenos Fogos, two small flames – evoking the impressions of a ballpoint pen tip, a burning writing – tensely settle in the ether of the small sheet of paper, which turns enormous.

This aggrandizing process may have led Tomás Cunha Ferreira to describe Leonilson’s work as an intensification. His presence in the exhibition is not entirely rendered unintelligible by this – there is a discreet intensity and purpose in the way he adapts to Leonilson: for example, the green embroidery he has placed next to the Brazilian artist’s expressive plastic self-portrait. It is an abstract and violent vertigo between a waterfall and gushing blood; and the work he created in dialogue with Saints, fools, toys, where he sought to bring to life the imagination of Leonilson’s drawing, is composed of a quasi-flag pinned by the cloth to the ceiling, guiding the pointed spike to the level of our gaze – an hinting relationship when we analyse the inevitable politico-cultural dialogue between the two artists: the Portuguese Tomás and the Brazilian Leonilson.

This relational crossword also takes account of the gallery: consider Tomás’ drawings on the windowsills. Some replicate them, others want to condense the city tile into a dense layer of cobalt blue liquid; collages where printed paper is superimposed on a written paper, on images. A squared paper cries DESVIO in wide and narrow letters, a phrase that goes from zero to everything, and works that stick to the wall, wanting to calculate it, understand it, transforming itself into space. Both artists unite on a common premise: the triumph of chance as a passage to the infinite.

The exhibition’s major surprise lies in a work whose first thing we see is its reverse. To get closer, we have to go around it from the right: we see an immense canvas, Cara e Coroa, (always “and” and never “or”; always the sum, never the otherness in Leonilson’s work) where there are two sides of the same coin – in their textured and carnal figuration they resemble two banana slices. The work is large enough to swallow us up but refuses to present itself through impact and ravishment. Its identity seems to lie in the first estrangement we feel on seeing it from the side – it is a side view, sideways, parallel, instinctive, inconsequential. The unexpected scale is striking when we think of the other works by the Brazilian artist presented here. Small and pure gems, such as the cabochons painted in 3 stones searching for your eyes.

This delicate weaving of affections leads us to embroidery, a decisive element in the Brazilian artist’s work. It is brought to mind by Tomás, given the unfortunate absence of originals on display. The yellow wrapping, an envelope with too many folds, arranged against the background of several drawings and collages in the exhibition’s first room, is attractive. Or the massive piece in the same space, an irregular polygon like an eaten rectangle, where colours, movements, purposefully irregular hems, diaries of expression are randomly assembled – Leonilson’s belief in the ability to interweave two opposing points.

For all its clustering dimensions, this exhibition is above all a place of memory. All connections and erasures are made in memory of Leonilson, replicating his vision and thought. As the only exhibition room text says, right at the beginning: “In 1993, José Leonilson died at the age of 36, a victim of AIDS, having created over 4000 works. This exhibition is the consequence of an invitation made by Brotéria to the artist Tomás Cunha Ferreira to create a dialogue with some of José Leonilson’s pieces”. From the outset, we are warned of the place we are about to enter, a living grave, a sacred space, apparently bewildering. This requires an ability to ignite, by magnifying all the details, like a map we see to remind us of the place it describes. This exhibition is a map – one we wanted to be more complete, more definitive, but which never refuses to fulfill us. We ask for directions.

Pequenos Fogos by José Leonilson and Tomás Cunha Ferreira is on view at Brotéria, in Lisbon, until February 26.